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THE NATURE OF 

MOVEMENT AND ACTION ERRORS 

PRODUCED BY BRAIN-INJURED PATIENTS 



BY 
BETH L. MACAULEY 












A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL 

OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT 

OF THE REQUIREMENTS FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 

UNIVERSITY OF FLORIDA 

1998 



Copyright 1998 

by 
Beth L. Macauley 



For Shawn, 
My gift from God 



ACKNOWLEDGEMENTS 
I would like to begin by extending a very special thank you to Leslie J. Gonzalez- 
Rothi, Ph.D., for her unwavering support and encouragement as I pursued the doctoral 
degree. I can remember her coming into my "office" during my VA traineeship in 1989 
and saying, "You should get a Ph.D. Think about it." Since that time, her mentorship 
has been invaluable as she imparted her extensive knowledge in the realm of neurogenic 
communication disorders, her expertise in patient care and being an advocate for her 
patients, as well as her personal morals and standards on being a well-rounded individual 
and dedicated wife and mother. I am honored to have her as not only a mentor but also a 
friend. 

Another special thank you goes to Kenneth M. Heilman, M.D., not only for his 
support as I served as a research assistant under his grants, but also for imparting his 
expertise with great enthusiasm to those working under his supervision. Dr. Heilman's 
encouragement and support allowed undergraduate students, graduate students, neurology 
residents, and neurology, psychology, and speech pathology faculty to work together in a 
smooth, caring, "family" atmosphere which is rare and unique in the realm of higher 
education. My skills and knowledge and ability to work in collaborative teams, as well 
as my respect for other disciplines, are the direct result of Dr. Heilman's influence and 
guidance. 

Other special thank yous go to Bruce Crosson, Ph.D., Linda J. Lombardino, 
Ph.D., and Ira Fischler, Ph.D., for their invaluable comments, suggestions, and 



IV 



encouragement given as part of my doctoral committee. These three elite faculty 
members have been superb teachers as well as supporters during my graduate career. 

I can not say enough about my faculty colleagues in the Department of Speech 
and Hearing Sciences at Washington State University. My chairman, Gail D. Chermak, 
Ph.D., is a strong advocate for junior faculty and was gracious in allowing me a reprieve 
of some faculty duties in order to concentrate and complete this dissertation. Her 
unwavering encouragement and support has been a blessing to me as I made the 
transition from graduate student to faculty. The other members of the department, Jeanne 
Johnson, Ph.D., Chuck Madison, Ph.D., Tony Seikel, Ph.D., Leslie Power, M.S., and 
Linda Vogel, M.S., have also given of themselves and served as mentors and friends 
during my initial years in their department. Their encouragement, support, and faith that 
I would finish the dissertation were never far from my mind. I can honestly say that 
without their "reality checks," continuous encouragement, and willingness to ease my 
load by increasing theirs, I would not have been able to finish. 

More thank yous go to my graduate students, Holly Wiseman, Stacy Wendel, 
Maria McClelland, and Erin Beneteau, at University Programs in Communication 
Disorders (UPCD), a cooperative graduate program in speech-language pathology and 
audiology between Washington State University and Eastern Washington University. 
These students willingly tolerated the training protocols and were genuinely excited to be 
taking part in research opportunities and endeavors. 

I also wish to thank Robert Short, Ph.D., of the Washington Institute for Mental 
Illness Research and Training (WIMIRT) for his assistance with the statistics. 



A huge thank you goes to my husband often years, Shawn P. Macauley, Ph.D., 
for his unwavering encouragement, prods in the rear to keep moving along, and for never 
doubting that I could get it done. His ability to encourage me in the midst of dealing with 
an acquired disability that affected his vestibular system and resulted in physical, visual, 
and cognitive impairments, has been a blessing above and beyond expectations. His 
unconditional love, support, and assistance allowed me to focus on writing without 
feeling too guilty about not keeping up with family responsibilities. Thank you also to 
my girls, seven year old Erin and three year old Emily, and my boy, three month old 
Evan, for their unconditional love as well as their acceptance of "Mommy's computer 
time," take-out twice a week, and piles of dirty laundry. Erin and Emily were always 
ready with a hug and a kiss whenever they were needed (and even when they were not 
needed) while Evan's smiles melted my heart and put everything in perspective. 

I also wish to thank my parents, John and Barbara Martin of Bradenton, Florida 
for their unconditional love, unwavering support and encouragement throughout my 
college career. They never doubted my abilities or decisions and were always looking for 
ways to help and show their support. I also wish to thank my in-laws, Curtis and Karen 
Winters of North Bangor, New York, for always being a phone call away to impart 
guidance, encouragement, and support through the dissertation years. 

Last, but certainly not least, I wish to thank my Lord and Savior, Jesus Christ, for 
His personal involvement in my life. I am nothing without Christ and my work is a 
testimony to the grace that He has given. I honestly believe that without Christ walking 
by my side and carrying me when necessary, I would not have finished this research 
endeavor, especially with the life-changing trials that have occurred within the past year. 



VI 



He started me on this journey and He has never failed to be there throughout. A special 
thank you to my dear friend, Priscilla Welbourn, who never let me forget what was most 
important in life and encouraged me to keep my feet firmly planted on the Rock while 
reaching for the stars. Her unconditional friendship and unwavering support during the 
final writing stages of this dissertation has been a blessed and treasured gift from the 
Lord. 



Vll 



TABLE OF CONTENTS 

Page 

ACKNOWLEDGEMENTS iv 

LIST OF TABLES x 

LIST OF FIGURES xii 

ABSTRACT xiii 

CHAPTER 

ONE REVIEW OF THE LITERATURE AND STATEMENT OF 

THE PROBLEM 1 

Introduction 1 

Review of the Literature 3 

Historical Perspectives and Theoretical 

Models of Apraxia 3 

Cognitive Neuropsychological Model 

Of Limb Praxis and Apraxia 12 

Right Hemisphere Contributions to Praxis 19 

The Ecology of Apraxia 21 

Significance to Clinicians and Patients 21 

Apraxia in Natural Contexts 23 

The Relationship Between Apraxia and Pragmatic Action 38 

Predictions of the Proposed Relationship Between 

Movements and Actions 49 

Classification of Action Errors 53 

Statement of the Problem 56 

TWO METHODS 63 

Subjects 63 

Materials and Methods 67 

Evaluation of Independent Variables 68 

Disorders of Action Planning and Organization 68 

Disorders of Learned, Skilled Movement 69 

Disorders of Tool-Object-Function Knowledge 72 

viii 



Disorders of Supervisory Attention/Working Memory 73 

Disorders of Language 74 

Neglect 74 

Evaluation of Dependent Variable 75 

Rater Training 79 

Statistical Analyses 80 

THREE RESULTS 82 

Experimental Results 82 

Research Questions 85 

Research Question #1 85 

Research Question #2a 87 

Research Question #2b 93 

Summary of Findings 98 

FOUR DISCUSSION 101 

Research Questions 103 

Methodological Issues and Limitations of the Study 1 1 1 

Implications for Future Research 113 

Clinical Implications 116 

APPENDICES 

A GESTURE TO COMMAND SUBTEST - RANDOMIZED 

FORMS A&B 119 

B TOOL-OBJECT MATCHING TEST 123 

C STANDARDIZED SCORES FOR TRAILS A & B 124 

REFERENCES 125 

BIOGRAPHICAL SKETCH 132 



IX 



LIST OF TABLES 

Table E^ 

2-1 LBD Subject Identification 65 

2-2 RBD Subject Identification 66 

2-3 Control Subject Identification • 67 

3-1 Descriptive Statistics for Each Group on Measures of 

Independent Variables 84 

3-2 Overall Kruskall- Wallace ANOVA for Errors 

Produced During the Meal 85 

3-3 Comparison of LBD and RBD Groups with Normal Controls 86 

3-4 Pearson Product Moment Correlation Report 88 

3-5 Average Number of Errors Produced by All Subjects when 
Divided into Two Groups According to Cut-off Score 
For Each Test 89 

3-6 Average Number of Errors by Specific Error Type Produced 

By LBD, RBD, and Control Groups 90 

3-7 Results of Multiple Stepwise Regression Analysis Between 
Independent Variables and Total Errors Produced During 
the Meal 94 

3-8 Results of Multiple Stepwise Regression Analysis Between 
Independent Variables and Tool Errors Produced During 
the Meal 94 

3-9 Results of Multiple Stepwise Regression Analysis Between 

Independent Variables and Non-Tool Errors Produced During 

the Meal 95 



3-10 Results of Multiple Stepwise Regression Analysis Between 

Independent Variables and Misuse Errors Produced During 

the Meal 95 

3-11 Results of Multiple Stepwise Regression Analysis Between 

Independent Variables and Misselection Errors Produced During 

the Meal 96 

3-12 Results of Multiple Stepwise Regression Analysis Between 

Independent Variables and Movement Errors Produced During 

the Meal 96 

3-13 Results of Multiple Stepwise Regression Analysis Between 
Independent Variables and INT Errors Produced During 
the Meal 97 

3-14 Results of Multiple Stepwise Regression Analysis Between 

Independent Variables and Sequence Errors Produced During 

the Meal 97 

3-15 Results of Multiple Stepwise Regression Analysis Between 

Independent Variables and Timing Errors Produced During 

the Meal 98 

3-16 Results of Multiple Stepwise Regression Analysis Between 

Independent Variables and Quantity Errors Produced During 

the Meal 98 






XI 



LIST OF FIGURES 

Figure Eage 

1-1 Liepmann's Model of Praxis 6 

1-2 Geschwind's Model of Praxis 9 

1-3 Heilman and Rothi's Model of Praxis 1 1 

1-4 Cognitive Neuropsychological Model of Apraxia 13 

1-5 Delineation of Gesture to Command Pathway 14 

1-6 Delineation of Gesture to Visually Presented Object Pathway 18 

1 -7 Schematic Representation of Misuse and Mis-Selection 

Action Errors 28 

1-8 Schematic Interpretation of the Unified Hypothesis 36 

1-9 Relationship Between Actions and Movements 40 

1-10 Breakdown of Low Level Schemas 41 

1-1 1 Breakdown of High Level Schemas 44 

1-12 Addition of Perceptual Input to Low Level Schemas 46 

1-13 Addition of Semantic System to High Level Schemas 47 

1-14 Proposed Relationship Between Apraxia and Pragmatic Action 48 

2-1 The Tower of London 70 



Xll 



Abstract of Dissertation Presented to the Graduate School 

of the University of Florida in Partial Fulfillment of the 

Requirements for the Degree of Doctor of Philosophy 

THE NATURE OF 

MOVEMENT AND ACTION ERRORS 

PRODUCED BY BRAIN-INJURED PATIENTS 

By 

Beth L. Macauley 

August 1998 

Chair: Leslie J. Gonzalez-Rothi, Ph.D. 

Major Department: Communication Processes and Disorders 

Some patients with brain damage produce action errors during activities of daily 
living. Investigators in recent research reports have examined the planning, organization, 
and production of these action errors through different theoretical models with different 
inherent assumptions and predictions, using different research hypotheses and evaluation 
criteria, and including subjects with heterogeneous etiologies of brain damage. The 
current study describes a proposed relationship between apraxia and pragmatic action that 
serves as a framework for the examination of the nature of movement and action errors 
produced by brain-injured patients. The hypothesized relationship between apraxia and 
pragmatic action can be divided into two parts—high level schemas associated with 
executive function, supervisory attention/working memory, and the conceptual 
knowledge of the relationship between tools and actions, and low level schemas 
associated with the praxis system which mediates learned skilled movements. Forty 

xiii 



subjects participated in this study-twenty left brain damaged patients (LBD), ten right 
brain damaged patients (RBD), and ten non-brain damaged control subjects. All subjects 
underwent an evaluation that measured high and/or low schema deficits and were 
videotaped while engaged in an activity of daily living, eating a meal. The videotapes 
were scored for presence of action and movement errors. Results indicated that both 
brain-injured groups significantly differed from the control group in total number of 
errors produced. The LBD group produced more tool errors than the RBD group while 
both the LBD and the RBD group produced significantly more non-tool errors than the 
control group but did not differ from each other. Additionally, production of specific 
error types during the meal correlated highly with a measure of high level schema deficits 
and a measure of low level schema deficits. Therefore, both high and low level schema 
deficits contribute to production of action errors. Additionally, the results appear to 
indicate that brain damage to either hemisphere can result in production of action errors 
in the natural environment. 












XIV 



CHAPTER ONE 

REVIEW OF THE LITERATURE AND 

STATEMENT OF THE PROBLEM 

Introduction 

Purposeful movements, defined as intentional "changes in place, position, or 

posture" (Webster, 1981, p.747), that have direct purpose or aim, and goal-directed 

actions, defined as "acts of will accomplished over a period of time in stages" 

(Webster, 1981, p. 12) are learned throughout life as people interact with their 

environment. The loss of the ability to produce purposeful, skilled movements as the 

result of brain damage has been termed apraxia (Rothi & Heilman, 1997). Liepmann 

(1920) defined apraxia as an impairment in the production of learned (or skilled) 

movements not caused by weakness, paralysis, incoordination, or sensory loss 

(Liepmann, 1920). Apraxia is manifested in a person's inability to "move the moveable 

parts of the body in a purposeful manner even though motility is preserved" (Liepmann, 

1900/1977, p.161). 

A deficit in the ability to produce goal-directed actions has been called frontal 
apraxia by Mayer, Reed, Schwartz, Montgomery, and Palmer (1990), Schwartz, Reed, 
Montgomery, Palmer, and Mayer (1991), Schwartz, Mayer, DeSalme, and Montgomery 
(1993), Schwartz, Montgomery, DeSalme, Ochipa, Coslett, and Mayer (1995), and 
Schwartz and Buxbaum (1997) and a deficit in managerial knowledge by Sirigu, 
Cohen, Duhamel, Pillon, Dubois, and Agid (1995), Sirigu, Zalla, Pillon, Grafman, 
Agid, and Dubois (1995, 1996), and Sirigu, Zalla, Pillon, Grafman, Dubois, and Agid 



l 



(1996). Specifically, both frontal apraxia and deficits in managerial knowledge were 
defined as impairments in the planning and sequential hierarchical organization of 
actions required to obtain a desired goal (Schwartz & Buxbaum, 1997; Sirigu et al., 

1995). 

Mayer et al. (1990), Schwartz et al. (1991, 1993, 1995), and Schwartz and 
Buxbaum (1997) reported that brain damaged patients with frontal apraxia produce 
errors of action while performing goal-directed activities of daily living such as 
preparing coffee and brushing teeth. These learned, goal-directed actions were 
subsequently labeled "pragmatic action" by Schwartz and Buxbaum (1997). Ochipa, 
Rothi, and Heilman (1989) reported a brain damaged patient with ideational/conceptual 
apraxia who made errors of action while eating a meal and brushing teeth, both 
"pragmatic actions as defined by Schwartz and Buxbaum (1997). Foundas, Macauley, 
Raymer, Maher, Rothi, and Heilman (1995) reported that brain damaged patients with 
ideomotor apraxia made action errors while performing the pragmatic action of eating a 
meal. Each of the above studies documented action errors in goal-directed activities of 
daily living. However, each of the above researchers approached the study of action 
and action errors through different theoretical models with different predictions and 
assumptions. Mayer et al. (1990), Schwartz et al. (1991, 1993, 1995), and Schwartz 
and Buxbaum (1997) approached the study of pragmatic action through the Unified 
Hypothesis, a theoretical model based on the activation-trigger-schema (ATS) 
framework proposed by Norman and Shallice (1986). The ATS framework for 
production of action was derived from the study of normal subjects (Norman & 
Shallice, 1986). Ochipa et al. (1989) and Foundas et al. (1995) approached the study of 



pragmatic action through the Cognitive Neuropsychological Model of Limb Praxis and 
Apraxia proposed by Rothi, Ochipa and Heilman (1991, 1997). The Cognitive 
Neuropsychological Model of Limb Praxis and Apraxia was derived from the study of 
brain injured patients (Rothi et al, 1991). In order to systematically study errors 
produced during pragmatic actions, a theoretical model is needed that explains the 
relationship between frontal apraxia, conceptual/ ideational apraxia, and ideomotor 
apraxia and incorporates action information from the Unified Hypothesis (Schwartz & 
Buxbaum, 1997) and movement information from the Cognitive Neuropsychological 
Model of Limb Praxis and Apraxia (Rothi et al, 1992, 1997). The resulting combined 
model can then be used to make predictions about pragmatic errors which can be 
subsequently studied. The purpose of the present study is to describe a theoretical 
model of pragmatic action based on Schwartz and Buxbaum (1997) and Rothi et al. 
(1997) which is then used as a framework to examine the nature of movement and 
action errors produced by brain-injured patients. Pertinent literature is reviewed 
relating to the genesis and growth of the study of movements and actions. 

Review of the Literature 
Historical Perspectives and Theoretical Models of Apraxia 

Steinthal, in the late 1800s, was the first to use the term apraxia in describing a 
disturbance in skilled limb movements as the result of brain damage (cited in Hecaen & 
Rondot, 1985). Steinthal wrote that apraxia consisted of a disturbance in the 
relationship between movements and the objects upon which the movements were 
enacted (cited in Hecaen & Rondot, 1985). Subsequently, there was a lack of 
consensus in discussions of the mechanism for and definition of apraxia. For example, 



other researchers had observed the disturbances of object related movements in aphasic 
patients but attributed both deficits to asymbolia, a generalized disturbance in the 
comprehension or production of symbols in any modality, including language and 
gesture (Finkelnstein, cited in Duffy & Liles, 1979; Critchley, 1939). Goldstein (1948) 
also related disorders of action to the patient's aphasia and included skilled movement 
problems within a definition of aphasia. Pick (1905), however, defined apraxia as an 
asymbolia which was not included within a definition of aphasia. Another mechanism 
proposed to explain apraxia was posited by Kussmaul (cited in Hecaen & Rondot, 
1985) who defined apraxia as an agnosia, an impairment in the recognition of tools, 
which then affects the movements produced with tools. In 1905, Liepmann described a 
patient, who presented with a severe inability to produce volitional movements with the 
left hand as well as profound aphasia. Liepmann's point in describing this case was that 
a disorder of language or gnosis could not explain apraxia of only one hand. 
Movement failures created by language or gnosis deficits would affect both hands. 
Thus, Liepmann (1900/1977, 1905a/1980a, 1905b/1980b, 1907/1980c, 1920) was the 
first to describe the mechanism of apraxia as a disorder of movement planning. 

Liepmann (1905b/1980b) studied 89 brain-damaged patients, 42 with left 
hemiplegia (thus suspected to have right hemisphere lesions), 41 with right hemiplegia 
(thus suspected to have left hemisphere lesions), 5 non-hemiplegic with aphasia (left 
hemisphere lesions), and one who was neither hemiparetic or aphasic but was apraxic. 
The patients were asked to produce three types of movements - 1) expressive 
movements such as waving and saluting; 2) transitive and intransitive movements to 
command (from memory) such as playing an organ grinder and snapping the fingers; 



and 3) manipulations of actual tools such as combing hair with a comb and writing with 
a pen. Liepmann found that the patients with right hemisphere damage rarely made 
errors on these tasks whereas the patients with left hemisphere damage made frequent 
errors. Within the groups of patients with left hemisphere damage, approximately half 
showed evidence of apraxia and of these, twenty-five percent showed impairments 
when manipulating the actual tools (Liepmann, 1905b/ 1980b). Based upon these 
observations, Liepmann proposed that the left hemisphere, specifically the parietal 
region, was responsible for the skilled production of both hands (Liepmann, 
1905b/1980b). He argued that the right hemisphere is dependent upon the plans and 
directives of the left hemisphere for learned movement and that the right hemisphere 
receives movement planning information from the left hemisphere via the corpus 
callosum. Liepmann proposed the existence of movement formulae which he defined 
as knowledge of the course of action (time-space sequences) required to complete an 
action goal as well as the semantic information about the tool and object used. The 
movement formulae may be implemented by retrieval of innervatory patterns 
(configurations of neural connections specialized for particular movement patterns) 
which communicate directly with the motor system for movement production (Figure 
1-1) (Liepmann, 1905b/1980b). 

Additionally, further support for Liepmann's proposal that the left hemisphere 
was responsible for the skilled movements of both hands was found in the case 
described by Liepmann and Maas (1907) of a patient with a lesion of the corpus 
callosum who was unable to produce skilled movements with his nonparalyzed left 



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Figure 1-1. Liepmann's model of praxis (taken from Rothi, Ochipa, & Heilman, 1991). 



hand. He was unable to write and could not even bring his hand into the writing 
position. The patient also showed deficits in using actual tools/objects. Liepmann 
hypothesized that the effect of corpus callosum lesion in this case was to disconnect the 
movement formulae of the left hemisphere from the primary motor cortex of the right 
hemisphere-lesion A in Figure 1-1 (Liepmann & Maas, 1907). 

Subsequently, Liepmann (1905a/1980a, 1905b/1980b) described three subtypes 
of apraxia-limb kinetic apraxia, ideo-kinetic or motor apraxia, and ideational apraxia. 
Limb kinetic apraxia was described as a loss of the kinetic components of engrams 
resulting in coarse or unrefined movements with movements that no longer have the 
appearance of being practiced over time. Ideo-kinetic or ideomotor apraxia was 
described as a loss of the voluntary ability to perform learned movements. Ideational 
apraxia was described as an impairment of ideational (conceptual) knowledge resulting 
in loss of the conceptual linkage between tools and their respective actions as well as 
the ability to sequence correctly produced movements (Liepmann, 1905a/1980a, 
1905b/1980b). Integral movements may be left out of a series, produced in the wrong 
order, or correct movements may be produced with the wrong tools (cited in Brown, 
1988). By describing these praxis subtypes, Liepmann (1905a/1980a, 1905b/1980b) 
proposed that praxis is supported by a multicomponential system that can be 
differentially impaired. 

Liepmann's proposals were resurrected by Geschwind in 1965 who discussed 
them in the light of new human and animal data. Geschwind supported the notion of 
the dominance of the left hemisphere for learned movement skill and of the existence of 
movement formulae or memories (stored representations). He also supported 



Liepmann's statements that apraxia resulted from lesions in the dominant parietal 
region but argued that the important area was the underlying white matter pathways, 
specifically the arcuate fasciculus, and not the cortex. 

Geschwind proposed that in the left hemisphere, the white matter pathway that 
runs deep to the supramarginal gyrus connecting the visual association areas and speech 
areas to the frontal lobes is the pathway by which motor responses are carried out in 
response to verbal and visual stimuli. These pathways terminate in motor association 
area, Brodman's area 6 (Geschwind, 1965). Movement information processed by area 6 
is then relayed to the ipsilateral primary motor cortex, Brodman's area 4, as well as the 
contralateral motor association area, area 6. Movement information processed by 
contralateral area 6 is then relayed to it's affiliated primary motor cortex, area 4. (See 
Figure 1-2.) 

Based upon this neural mechanism, Geschwind proposed that the apraxia of the 
left arm in a patient with right hemiplegia is not caused by the same lesion that caused 
the hemiplegia. Rather, the apraxia results from coincidental damage to either area 6, 
the callosal fibers connecting the left area 6 and the right area 6, or to the projections to 
area 6 from the parietal lobe. This argument implied that a lesion anterior to the left 
motor cortex which affects area 6 but spares area 4 should result in a bilateral apraxia. 
However, Geschwind stated that as of his writing, no such cases have been described 
presumably because lesions of left area 6 would most likely also affect area 4 due to 
their anatomical contiguity. 




Figure 1-2. Geschwind's model of praxis. Lateral view of the left hemisphere. 
AF = arcuate fasciculus; SMA = supplemental motor area or motor 
association cortex; MC=primary motor cortex; VAC = visual 
association cortex; VC = primary visual cortex. The arrows indicate 
major connections of the areas shown (from Heilman & Rothi, 1985). 






10 



Assuming that visuokinesthetic engrams (Liepmann's movement formulae) of 
the left parietal lobe are important for correct production of gesture as well as critical to 
the decoding of seen, familiar gestures, Heilman, Rothi, & Valenstein (1982) postulated 
that damage to the visuokinesthetic engrams would result in difficulty with both the 
comprehension and production of gesture. The authors argued that measuring a 
patient's ability to discriminate well-performed from poorly performed movements may 
enable the clinician to determine whether or not a patient's apraxia resulted from 
destruction of these engrams through lesions involving posterior cortical regions: 
specifically left parietal lobe. An apraxic patient with preserved visuokinesthetic 
engrams would be able to discriminate between good and poor performance while an 
apraxic patient with damage to the visuokinesthetic engrams would not be able to make 
that discrimination. The authors tested this theory by giving 20 apraxic subjects a 
gesture discrimination test. The examiner named a target action and the subjects were 
asked to watch a videotape of gesture performances and choose the performance out of 
three possible for each command that best represented the named target. Patients with 
more difficulty discriminating the gesture productions had posterior lesions (and 
presumably damaged visuokinesthetic engrams.) Based on these results, Heilman et al. 
(1982) discussed the possibility of two types of ideomotor apraxia: one type which 
presents with poor production and comprehension of gestures and results from damage 
to the left supramarginal or angular gyrus in the parietal lobe and a second type which 
presents with praxis production problems alone and results from damage that does not 
involve this parietal region. (See Figure 1-3.) 



11 




Figure 1-3. Heilman and Rothi's Model of Praxis. View from top of brain. 

W = Wernicke's area; VA = primary visual area; VAA ■ visual association 
area; AG = angular gyrus; SMG = supramarginal gyrus; PM - premotor 
area (motor association cortex); M = motor cortex; CC = corpus callosum; 
LH = left hemisphere; RH - right hemisphere. The arrows indicate major 
connections of the areas shown (from Heilman & Rothi, 1985). 



12 



Cognitive Neuropsychological Model of Limb Praxis and Apraxia 

Recognizing Liepmann's assertion that skilled praxis was the product of a 
complex multi-component system and also recognizing that numerous cases were 
described in the literature that reflected behavioral fractionation of praxis related 
behavior, Rothi, Ochipa, and Heilman (1991, 1997) proposed a cognitive neuro- 
psychological model of apraxia in an attempt to capture these dissociations. A 
schematic representation of this model can be found in Figure 1-4. In this model, the 
term "action-lexicon" is used as the gestural equivalent to the term "lexicon" used in 
language which distinguishes that part of the language system which gives a processing 
advantage for words that the person has previously experienced (Rothi & Heilman, 
1985). Therefore, the action-lexicon was defined as that part of the praxis system 
which gives a processing advantage for movements that the person has previously 
produced (Rothi et at., 1991, 1997). That is, it is an action memory. The action lexicon 
was divided into input and output components to account for patients who demonstrate 
spared gesture comprehension with impaired imitation and gesture to command. The 
authors stated that for these patients, spoken language gains access to the output action 
lexicon via semantics without being processed by the input action lexicon (Figure 1-5). 
In contrast, deficits in gesturing to command with spared repetition and spared 
comprehension were explained by dysfunction at or after the output action lexicon 
while sparing the innervatory patterns (Rothi et al. 1991). 

DeRenzi, Faglioni, and Sorgato (1982) and Rothi, Mack, and Heilman (1986) 
discussed cases that provide evidence for modality-specific apraxic deficits. That is, 
the praxis performance of the reported patients differed as a result of input modality 



13 



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(e.g. auditory, tactile, or visual). Rothi et al. (1991, 1997) accounted for the differences 
in performance as a result of input modality by incorporating separate input systems for 
visually presented gestural information, tactily presented (no visual input), and 
auditorily presented verbal information. For visual/gestural information, the 
product of visual analyses accesses either the input action lexicon or the innervatory 
patterns directly (Figure 1-4). The presence of this direct route from visual analysis to 
innervatory patterns may account for those patients who can imitate gestures but can 
not discriminate or comprehend gestures (Rothi et al, 1986). That is, in cases where 
gesture imitation is not possible through input to output lexicons or input lexicon to 
semantics to output lexicon, gesture imitation may occur through a "non-lexical" route 
similar to the route in which nonwords are imitated in language. For visual/ object 
information, visual analyses activate the object recognition system which produces a 
structural description of the viewed object. It is hypothesized that the structural 
descriptions then access either the semantic system or action output lexicon. The 
connection between the visual analyses and the action output lexicon may allow for the 
production of gesture from the visual modality without accessing semantics. Visual 
object information being processed accesses the action output lexicon without prior 
processing by the action input lexicon because the action output lexicon pertains to 
codes of the "to-be-performed" actions while the action input lexicon pertains to codes 
of "perceived" actions (Rothi et al, 1997). This route (visual analysis to action output 
lexicon) may account for the ability of certain patients who can not comprehend the 
meaning of the gestures because of a failure of the action semantic system, but can 
accurately produce gestures to shown tools. These patients may have intact 



16 



comprehension of objects but impaired comprehension of actions thereby suggesting a 
dissociation within the semantic system for information about objects and information 
about actions. Auditory/verbal input is transmitted to auditory association areas that 
perform auditory analyses and activate the phonological input lexicon. Information 
processed by the action input lexicon can be analyzed semantically by the semantic 
system or phonologically for output by the verbal output lexicon. In figure 1-4, the line 
connecting the region where auditory analysis is performed to the phonological buffer 
may be the route that accounts for those patients who can repeat but not comprehend 
verbal information (Rothi etal, 1991). 

Roy and Square (1985) propose that praxis processing involves not only 
information about gestural production but conceptual information as well. Within the 
Rothi et ai, (1991, 1997) model, conceptual analysis of praxis is accomplished by the 
action semantic component. Roy and Square (1985) and Raymer and Ochipa (1997) 
describe praxis conceptual knowledge as knowledge of the functions of tools and 
objects, knowledge of actions not related to tools and objects, and knowledge of 
combining actions into sequences. Rothi et ai, (1991, 1997) state that actions depend 
upon the interaction between the conceptual knowledge described above and the 
sensorimotor information contained in the motor programs. The action semantic 
system contains the conceptual knowledge relating to tools, objects, and actions. In 
figure 1-4, the line in the semantics area accommodates recent information that action 
semantics can be compartmentalized from nonaction semantics. Support for this 
separation within semantics is found in reports of patients with optic apraxia who were 
able to accurately gesture to command but were unable to accurately imitate the same 



17 



gestures or gesture to visually presented tools (Raymer, Greenwald, Richardson, Rothi, 
& Heilman, 1992) as well as studies of Alzheimer's patients with impaired action 
semantics with spared nonaction semantics and vice versa (Ochipa et al, 1992, 
Raymer, 1992). This separation also accommodates those researchers who claim that 
there are multiple semantic systems which reflect the modality and nature of input 
material (Beauvois & Saillant, 1985; Paivio, 1986; Shallice, 1987, 1988). 

By comparing patients' performance across tasks, researchers and clinicians 
may use this neuropsychological model to ascertain the nature of the processing 
damage and make predictions regarding performance. For example, when gesturing to 
command, patients would receive auditory/verbal information {e.g. "show me how to 
use a hammer") which would be processed phonologically by the phonological input 
lexicon followed by the conceptual analysis of the action semantic system. After 
semantic analysis, the information would be processed by the action output lexicon and 
the relevant innervatory patterns would be accessed for production of the gesture by the 
motor system (Figure 1-5). When gesturing to a visually presented tool/object, patients 
would visually analyze the tool/object and corresponding information would be utilized 
by the object recognition system with subsequent access to semantics, action output 
lexicon, and the innervatory patterns for production by the motor system (Figure 1-6). 
According to the model in Figure 1-6, patients must access semantics to gesture to 
command correctly but do not have to access semantics to gesture to a visually 
presented tool/object. Therefore, by comparing the patient's performance in these two 
tasks, researchers and clinicians may be able to evaluate the integrity of the semantic 
system. 



18 




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Right Hemi s phere Contributions to Praxis 

In addition to his proposals that the left hemisphere was dominant for learned, 
skilled movement, Liepmann also acknowledged that the right hemisphere may also 
have the ability to plan and generate skilled movement (Liepmann, 1905a/1980a, 
1907/1 980c, 1920). 

However, Liepmann considered the right hemisphere to be subordinate to the 
dominate left hemisphere and would require the activation of the movement formulae 
(visuokinesthetic engrams) of the left hemisphere for correct production of skilled 
movement in situations where the movements were done without manipulation of the 
actual tool and object. That is, the right hemisphere depends on the integrity of the left 
praxis system for production of learned, skilled movement in the absence of visual or 
tactile information. In other words, the right hemisphere relies on the intact left praxis 
system to produce correct actions when tools and objects are not used (Liepmann, 
1905a/1980a, 1920; Maher, 1995). 

This ability of the right hemisphere to produce correct movements and actions 
in context with actual tools and objects was confirmed by Rapcsak, Ochipa, Beeson, 
and Rubens (1993) who reported a patient, G.K., who suffered destruction of the entire 
left hemisphere following a massive stroke. G.K. was strongly right-handed and it 
could be hypothesized that the left hemisphere was dominate for language and praxis. 
However, results of complete and intensive praxis testing which evaluated each input 
and output modality for production and comprehension of learned, skilled movement 
indicated that G.K. was severely impaired in all praxis tasks when actual tools and/or 
objects were not used. In fact, G.K. reported no difficulty performing common 



20 



everyday tasks such as preparing meals and fixing household items in which tools and 
objects are used together and in the relevant context. 

Maher (1995) studied the role of the right hemisphere in production of learned, 
skilled movements by evaluating the temporal and spatial aspects of gestures produced 
by patients with left or right hemisphere brain lesions and matched normal control 
subjects using a scoring system described by Rothi, Mack, Verfaellie, Brown, and 
Heilman (1988). The subjects produced gestures to auditory command using the arm 
and hand ipsilateral to the side of lesion to control for possible effects of hemiparesis. 
The gestures were scored by two independent raters who were blind to the nature of the 
study. The raters received intensive training before each scoring session which resulted 
in high inter- and intra-rater reliability. The raters first scored the gestures pass/fail 
according to correctness. Then, if a gesture was scored as incorrect, error type(s) were 
awarded based on the above error classification system which included the following 
error types: internal configuration, external configuration, occurrence, amplitude, 
movement, and sequencing of movements (e.g., to use a key one must insert, turn, and 
remove the key in that order). Results of the study showed that the left brain lesioned 
subjects performed significantly worse than both the right brain lesioned subjects and 
normal control subjects overall. When frequency of each error type was compared 
across groups, there were significant differences for all error types except movement 
and amplitude. Pairwise comparisons were then performed to distinguish etiology of 
the differences. These comparisons suggested that the significant difference between 
the left and right brain lesioned subjects for movement errors can be accounted for by 
extremely poor performance by the left brain lesioned subjects when compared to the 



21 



other subject groups. This was a significant result because it supports the notion that 
the left hemisphere is dominate for praxis. Apraxia is inherently a disorder of learned, 
skilled movement and significant difficulty in the movement aspects of skilled 
movements should be observed following damage to this system. The pairwise 
comparisons also suggested that the significant difference for amplitude apects of 
movement occurred between the right brain lesioned subjects and the normal controls 
with no significant difference between the right and left brain lesioned groups. Maher 
(1995) proposed that this result suggests that both the right and left hemispheres could 
code spatial aspects of movement. 
The Ecology of Apraxia 
Significance to clinicians and patients 

Other than its lateralizing value, apraxia has not been considered of significant 
practical importance. DeRenzi (1985) said that apraxia rarely appears in everyday 
situations and only emerges "out of context as a purposeful response to an artificial 
request" (page 134.) Because ideomotor apraxia was considered to be an examination- 
bound symptom that would not attract a clinician's attention unless the clinician 
specifically looked for it, apraxia may have been overlooked and underestimated in 
brain damaged patients (DeRenzi, 1985). 

Many clinicians might agree that patients do not spontaneously complain of 
apraxic disturbances (Heilman & Rothi, 1985). One possible explanation for this is that 
apraxic patients may have anosognosia (unawareness of the disorder) for their praxis 
difficulties (Rothi et al, 1986). Another possible explanation is that patients with 
apraxia frequently have a co-occurring right hemiparesis. Therefore, patients may 



22 



associate their clumsiness to use of the non-dominant left hand for tasks in which they 
previously used their dominant right hand. While apraxia may be present, praxis 
performance may improve when manipulating actual objects or tools (Geschwind, 
1965) and caretakers or family members, who rarely have the opportunity to observe 
tool/object use pantomime, may not be aware of the disorder. In fact, many family 
members may provide assistance in self-care skills such as feeding and dressing for 
convenience and efficiency purposes (Heinemann, Roth, Ciehowski, & Betts, 1987). 
In a hospital or rehabilitation center, it is possible that the environment of the 
patients may be controlled and geared toward partial functional independence where a 
patient can complete at least part of a task independently. For example, in a nursing 
home environment it has been observed that when it is time for a patient to brush 
his/her teeth, the nurse may put the toothpaste on the toothbrush, hand the toothbrush to 
the patient, and tell the patient to "brush your teeth." It has also been observed that 
during mealtime, the nurse may prepare the food for the patient by cutting the meat, 
putting the straw in the drink and/or handing the correct utensil to the patient. A study 
by Heinemann and colleagues (1987), which examined functional outcome of stroke 
rehabilitation programs, found that all of the independence gained during rehabilitation 
in the area of feeding was lost by three months after discharge. They proposed that loss 
of a controlled environment that promoted functional independence (e.g., the caregiver 
no longer prepared the environment to maximize the patient's skills, but began to assist 
the patient directly) may explain this decline in function. 

Another study examined factors that influenced a person's ability to return to 
work after a stroke (Saeki, Ogata, Okubo, Takahashi, & Hoshuyama, 1993). The 






23 

authors followed 244 patients, ages 24 to 65, who were actively employed at the time of 
their strokes and extracted information from the admission medical records of each 
patient. Results indicated that 58% of the patients returned to work by the time of the 
follow-up which varied from 8 to 77 months post-stroke. The most important factor 
that determined a patient's ability to return to work was severity of muscle weakness on 
admission. The second most important factor was presence of apraxia. The odds of a 
patient without apraxia returning to work were determined to be four to five times 
greater than for patients with apraxia (Saeki et al, 1993). However, possible 
limitations of this study are that the authors combined ideomotor apraxia with 
ideational apraxia, dressing apraxia, and constructional apraxia in the analyses; none of 
which were operationally defined. As a result, it can not be determined which one or 
more types of apraxia affected the patients' ability to return to work or whether the 
authors' definition of apraxia was similar to or different from previously published 
definitions. 
Apraxia in natural contexts 

The first study to document the effects of apraxia in the non-clinical 
environment was conducted by Sundet, Finset, and Reinvang (1988). These 
researchers investigated variables that affected a patient's ability to function in the 
home environment following discharge from a rehabilitation hospital. They sent 
questionnaires to 68 left hemisphere stroke patients and 77 right hemisphere stroke 
patients six months after discharge from rehabilitation. The questionnaire focused upon 
activities of daily living and the amount of "dependency" the patients displayed in the 
home environment. Dependency was defined as the increased need for caregiver 



24 



assistance in performing tasks of daily living. The patients were asked 13 simply 
written yes/no questions such as "requires use of kitchen aids" and "requires help to 
dress" (Sundet et al, 1988, p.369). Caretakers were asked to answer the questions in 
the event that a patient could not. Sundet and colleagues compared the relationship 
between results of the questionnaire (measure of dependency) and neuropsychological 
deficits such as hemiplegia, aphasia, nonverbal memory deficits, neglect, and apraxia; 
the presence of which were determined by review of each patients' medical records. 
Results of the study indicated that the highest predictor of dependency for the left 
hemisphere damaged subjects was the presence of apraxia. 

Limitations of the Sundet et al. (1988) study include the authors' reliance upon a 
questionnaire filled out by caregivers rather than direct patient observation to determine 
the patients' ability to function independently in a natural environment and context. 
There was also a six month hiatus between the neuropsychological testing and 
determination of the patients' "dependency" during which time the patients' 
performance on the neuropsychological tests (and, in turn, the presence of 
neuropsychological deficits including apraxia they were reported to document) may 
have changed. Although a study by Rothi and Heilman (1985) documented that over 
80% of patients who are acutely apraxic remain apraxic six months later, it is unknown 
how many of the 68 left hemisphere damaged subjects in the Sundet et al. (1988) study 
would have been considered apraxic at the time of dependency determination. 

One study in which patients were directly observed and which did not have a 
hiatus between clinical examination and experimental procedures was conducted by 
Foundas, Macauley, Raymer, Maher, Rothi, and Heilman (1995). Foundas and 



25 



coworkers (1995) examined actual tool use during mealtime in 10 left hemisphere 
stroke patients and 10 neurologically normal controls matched for handedness, age, 
gender, and education. Subjects were tested for presence of aphasia and apraxia and 
then, on the same day as testing or no more than three days later, were videotaped while 
eating a meal. For each subject the meal tray was placed on a table in front of the 
subject and foil items such as a toothbrush, comb, and pen were included on the tray in 
addition to the standard tools and utensils for eating (spoon, fork, knife, napkin, and 
condiments). The location of the standard tools and the foils were counterbalanced to 
control for their left to right placement on the tray. The examiner left the room and no 
assistance was given to the subject in preparing or eating the food. 

Results of the Foundas et al (1995) study documented two main differences 
between the control and experimental subjects. The first difference became apparent 
when the stages of eating (preparatory, eating, and clean-up) were compared across 
groups. During the preparatory phase, behaviors included such things as opening 
condiment packages, placing the napkin on the lap, cutting the meat, and putting sugar 
in the tea. During the eating phase, the food was eaten. During the clean-up phase, 
behaviors such as putting the napkin back on the tray, putting the utensils on the plate, 
and pushing the tray away were accomplished. The first difference between the groups 
was that 80% of the control subjects proceeded through all three phases of the meal 
compared to only 20% of the experimental subjects. The authors reported that the 
control subjects respected the boundaries of each phase whereas the experimental 
subjects did not. That is, the control subjects showed clear, distinct beginning and end 
points of each phase while the experimental subjects tended to have preparatory, eating, 



26 



and clean-up actions interspersed randomly throughout the meal as if there was a lack 
of anticipation for pending task demands. The authors also reported that within the 
eating phase, the control subjects ate using eating patterns that were idiosyncratic 
within subjects but consistently developed across subjects. For example, a control 
subject might eat portions of the main course (e.g., meat) followed by the bread, the 
vegetables, and drink of tea and repeat this pattern over again until all food had been 
eaten. In contrast, the experimental subjects tended to eat in a more random fashion 
with no definable eating pattern. 

In the Foundas et al. (1995) study, the experimental subjects produced more 
"tool errors" (errors of action in using tools such as spoon, and fork) than "nontool 
errors" (errors of actions that do not involve tools such as wiping the face or moving 
the glass) while the control subjects did not produce any errors. One might suggest, 
however, that because the experimental subjects had a hemiparesis and the comparison 
group did not, the differences between the groups may be related to the presence of a 
primary motor defect in the apraxic group. However, an underlying motor system 
deficit could not explain the difference in eating praxis performance in these two 
groups because a motor deficit should have affected both tool and nontool actions 
equally, and it did not. Therefore, even though the experimental subjects had a right 
hemiparesis, the action errors they produced, selective only for praxis related to tool 
use, were not the result of an underlying motor problem. 

Results of the Foundas et al. (1995) study indicated that while the overall eating 
time of the experimental subjects did not differ from the control subjects, the 
experimental subjects made fewer actions in general, used fewer utensils, and often 



27 



misjudged the advantage of using a tool. The experimental subjects produced 
significantly more incorrect actions when compared to the controls and as a result were 
less efficient in executing individual tool actions. Tool misuse and mis-selection errors 
were produced by all but one experimental subject who happened to score within the 
normal range on the test for ideomotor apraxia. Errors such as eating ice cream with a 
fork (mis-selection), cutting with a spoon (misuse), stirring with a knife (misuse), and 
wiping one's face with a slice of bread (mis-selection) were observed. A schematic 
representation of misuse and mis-selection errors can be found in Figure 1-7. In 
contrast, the normal control subjects made more actions in general, used more utensils, 
and used the utensils correctly throughout the meal. The tool actions of the 
experimental subjects were often incomplete or imprecise so that a desired goal was not 
achieved. Foundase/ al. (1995) argued that the high correlation between number of 
action errors produced and presence of ideomotor apraxia suggested that ideomotor 
apraxia caused the production of action errors in this natural context. 

A series of studies by Schwartz and colleagues also examined action errors in 
activities of daily living by brain damaged subjects. The first study by Mayer, Reed, 
Schwartz, Montgomery, and Palmer (1990) examined a group of brain-injured patients 
in a rehabilitation hospital. Forty-five patients with traumatic brain injury and six 
patients with stroke were observed during activities of daily living such as brushing 
teeth and making coffee. The authors found that 49% of the patients produced errors of 
action during activities of daily living. Unfortunately, due to the nature of the brain 
damage of the patients they studied, it is not known whether the action errors were the 
result of the 






28 



Misuse 




object action 



Mis-selection 



tool 



tool 





Misuse and Mis-selection 



tool 



tool 





tool 




object action object action object action 



tool 




object action object action object action 



Figure 1-7. Schematic Representation of Misuse and Mis-selection Action Errors. 
// indicate location of error(s). 



29 



general intellectual impairment or executive function defects commonly found in 
traumatic brain injured patients or of apraxia. 

Mayer et al. (1990) developed a theory of action based upon Norman and 
Shallice's (1986) model of attentional control of action which proposes two modes of 
control of action, one which is automatic and one which requires deliberate attentional 
control. Mayer et al. (1990) studied the action productions within a natural context of 
45 patients with closed head injury and proposed that impairment of the deliberate 
attentional control route was the genesis for production of action errors in their patients 
with brain damage. For this study, an action coding system was developed that 
describes the sequence of actions produced by brain damaged patients as either A-l 
units (general actions, not task-specific such as rinsing a glass), A-2 units (specific, 
task-related actions such as unscrewing the cap from a toothpaste container), or crux A- 
1 units (the action that accomplishes the next goal such as squeezing the toothpaste 
onto the toothbrush when preparing to brush teeth). The action coding system enabled 
the researchers to examine which actions were produced out of sequence, were omitted, 
or were perseverated by applying the action coding system to a script of the patient's 
actions and examining the relationship and sequence of the A-l, A-2, and crux A-l 
units in the patient's production to that of a prototype script. 

Mayer et al. (1990) then applied the action coding system to a script of actions 
produced by a brain injured patient during a task of daily living. One patient, H.H., had 
suffered a bifrontal injury with resulting aphasia and callosal apraxia in which he was 
apraxic with his non-dominant left hand and not apraxic with his preferred right hand. 
H.H. was videotaped during breakfast and a script of his actions was written. The 



30 



action coding system was applied to the script to analyze action sequences. The authors 
reported that even though H.H. produced frequent errors such as pouring tomato juice 
on waffles and attempting to spoon oatmeal into tea, his main deficit was in the 
efficiency of his action plans. That is, A-l, A-2, and crux A-l units were produced 
randomly and not in a logical order or sequence to accomplish the goal of the task at 
hand. In addition, there was the appearance of action errors that included misuse and 
mis-selection of tools as well as movement errors that included sequencing and timing 
of movements. The authors argue that these errors, misuse and mis-selection of tools as 
well as sequence, were not a result of the patient's apraxia because "in the majority of 
patients with documented apraxia, there (was) no functional consequence of the apraxic 
impairment" (Mayer et al, 1990, p.280). Foundas and colleagues, however, would 
argue that the above statement is not an accurate assumption in that the authors did not 
test for apraxia and as a result could not speak towards the significance of apraxia to the 
production of action errors in their patients. 

Schwartz, Reed, Montgomery, Palmer, and Mayer (1991) continued their work 
by applying the action coding system to two specific tasks-making coffee and brushing 
teeth~as produced by H.H., the brain damaged patient described by Mayer et al. 
(1990). H.H. was videotaped performing these tasks in the natural environment and 
scripts of his actions were analyzed according to the action coding system described by 
Mayer, et al. (1990). The authors noted that H.H. had a higher susceptibility to object 
substitutions and object misuse as well as a variability of action errors across time. 
Regarding normal action processing, the authors argue that learned actions are not 



31 



executed as whole programs but are organized into hierarchies of temporally structured 
units that depend on the prefrontal area of the brain for integration and production. 

Based on the results of the study described above, Schwartz et al. (1991) 
proposed four theoretical foundations of intentional actions and action errors: the first 
tenet claims that intentional action involves activation of an action plan; the second 
claims that the planning and execution of intentional actions are closely coupled in real 
time; the third claims that intentional actions are integral to all purposeful behavior; and 
the fourth claims that errors of action occur due to weakening of the top-down 
formulation of action plans. This weakening of the action plans allows the patient to be 
influenced by irrelevant objects and actions leading to a susceptibility of object related 
errors of action. Schwartz and colleagues (1991) also proposed that the condition of 
action disorganization observed in brain injured patients while performing activities of 
daily living be termed frontal apraxia. 

The explanation of the mechanism of frontal apraxia offered by Schwartz et al. 
(1991) is not contradictory to Liepmann (1900/1977, 1905a/1980a, 1905b/1980b, 1907/ 
1980c, 1920) and Heilman and Rothi's (1985, 1993) description of movement 
memories. Rather, Liepmann, Heilman and Rothi's proposals focus upon a retrieval 
system for the memories of unique learned skilled movements that span from single 
discreet actions (the action lexicons) to subcomponents (innervatory patterns) of these 
actions. In contrast, the proposal of Schwartz et al. (1991) focuses upon the internal 
relationship between discreet component actions of larger action goals. Both Liepmann 
(1920) and Schwartz et al. (1991) use the term "frontal apraxia" to describe the 
movement/action errors that occur when the internal relationship between discreet 



32 



action representations in the larger action goal context have been loosened or 
disorganized by brain damage. 

Schwartz, Montgomery, DeSalme, Ochipa, Coslett, and Mayer (1995) expanded 
the study of action errors by examining J.K., a patient with traumatic brain injury, 
whose behavior was similar to the patient (H.H.) studied by Mayer et al. (1990) and 
Schwartz et al. (1991). J.K. was videotaped while eating breakfast and brushing his 
teeth and the tapes were scored according to the action coding system described by 
Mayer et al. (1990). J.K. also underwent a battery of neuropsychological tests that 
included object identification and recognition, conceptual/semantic knowledge, 
functional/use knowledge, gesture knowledge, gesture production, other language 
testing, and memory testing. Results indicated that J.K. evinced numerous action errors 
during the activities of daily living, especially tool misuse errors. The authors 
postulated that the tool errors were not due to a conceptual/ideational apraxia because 
J.K. was able to correctly identify tools by name and by function as well as match tools 
with their corresponding object. However, the authors argued that J.K.'s tool misuse 
errors were not the result of a weakened top-down processing of action plans found 
with frontal apraxia because J.K. was able to demonstrate or gesture the appropriate use 
for a tool from visual and tactile cues, a high level task (Schwartz et al, 1995). The 
authors concluded that in order to accommodate J.K.'s full range of performance, both a 
top-down and a bottom-up impairment of intentional action planning should be adopted 
(Schwartz et al, 1992). That is, the loosening or disorganization of relationships 
between discreet action representations could be the result of damage to either higher or 
lower order mechanisms within the action planning and movement production system. 






33 



Schwartz et al. (1993) adapted the action-trigger-schema (ATS) framework 
developed by Norman and Shallice (1986) as a means of organizing actions and 
classifying action errors. The ATS framework proposes that action plans are composed 
of schemas which are organized memory structures that integrate different types of 
information for use with actions. These schemas and their interrelations are developed 
over time through individual experiences and can generate positive or negative 
activation to specialized systems such as the motor system from the action plans. 
Familiar action sequences such as eating are represented by groups of schemas 
organized hierarchically. High level schemas occur in a top-down fashion while the 
low level schemas occur in an orderly fashion according to the logical progression of 
actions within the schema. For example, the higher level schema for eating breakfast 
would be the intent to eat and complete the meal while the lower level schemas would 
be those actions required to eat the meal such as opening a juice carton, picking up a 
fork, and taking a bite of food. Using the ATS framework, the authors proposed that 
action errors are due to the loss or instability of activation within the action schema 
network possibly due to a weakening of the connections among schemas (Schwartz et 

al, 1993). 

Schwartz et al. (1993) argue that a patient with frontal apraxia will produce 
errors differently during an activity of daily living than a patient with a disorder of 
attention. Specifically, a frontal apraxic patient with dysfunction in the ability to plan 
and coordinate action sequences may exhibit incoherence and intrusions of actions 
which result in a fragmentation of behavior. Patients with frontal apraxia may also use 
tools and objects in novel or bizarre ways because the action plan for using the tools 



34 



and objects is inaccurate, nonspecific, and faulty. In contrast, an attention disordered 
patient may exhibit intrusions of irrelevant actions and temporary derailments to other 
tasks resulting in inefficient but coherent action sequences. 

Schwartz et al. (1993) addressed the issue of whether the observed action errors 
were related to an ideational apraxia by comparing the action performance of H.H., a 
traumatic brain injured patient described in Schwartz et al. (1991), to the action 
performance of a left-handed, right hemisphere damaged patient described by Ochipa 
et al. (1989) who displayed ideational (conceptual) apraxia. Although both patients 
produced numerous errors of action during activities of daily living, H.H. evinced 
misuse of tools with spared tool function knowledge while the Ochipa et al. (1989) 
patient evinced spared production with impaired tool function knowledge. Schwartz et 
al. (1993) posited that frontal apraxia and ideational apraxia have different underlying 
mechanisms in that patients with ideational apraxia have impaired conceptual-semantic 
knowledge while patients with frontal apraxia have spared conceptual-semantic 

knowledge. 

Mayer et al. (1990) and Schwartz et al. (1991, 1993, 1995) also applied the 
action coding system to the performances of a subject who suffered a hemorrhagic 
stroke (J.H., discussed in Schwartz et al, 1991) and a subject who suffered diffuse 
damage following traumatic brain injury (J.K., discussed in Schwartz et al., 1993, 
1995) during two activities of daily living. Although the errors produced by the 
patients were described, the nature of the patients' brain damage did not allow the 
researchers to make conclusions about brain-behavior relationships. Both hemorrhagic 
strokes and traumatic brain injury may be associated with more damage to the brain 



35 



than appears on CT/MRI scans. One other limitation of this series of studies is that 
although it was not their intention to include ideomotor apraxia as a possible factor, 
ideomotor apraxia is likely to have been present in their cases and may have been an 

important factor. 

Schwartz and Buxbaum (1997) proposed a "Unified Hypothesis" to explain the 
errors of action observed in patients with frontal and/or ideational apraxia. The 
author's schematic representation of this hypothesis can be found in Figure 1- 8. The 
Unified Hypothesis is based upon the ATS framework which states that through 
experience and learning, higher level schemas organize lower level schemas into 
temporally ordered sequences. Experience and learning solidify connections between 
higher and lower level schemas for specific tasks making the retrieval of the lower level 
schemas automatic. For example, one higher level schema would contain information 
on the sequence of actions required to eat a meal and would automatically activate 
lower level schemas for cutting, drinking, wiping, and stirring, etc., as needed 
throughout the meal process. Another high level schema would contain information on 
the sequence of actions required to build and would activate lower level schemas for 
getting the permit, hiring architects, buying materials, putting in the foundation, etc. In 
turn, the schema for putting in the foundation would activate lower level schema for 
marking the ground, digging the hole, pouring the concrete, and etc. Whether a schema 
is considered "low" or "high" is determined by the relationship between schema within 
the goal of the task. Schwartz and Buxbaum (1997) differentiated between learned, 
routine actions and novel or nonroutine actions in that pre-existing connections existed 
between high level and low level schemas for learned, routine actions but not for novel 



36 






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or nonroutine actions. The pre-existing connections between higher and low level 
schemas allow learned, routine actions to become more automatic, but also more prone 
to error (Schwartz & Buxbaum, 1997; Reason, 1990). According to Schwartz and 
Buxbaum, (1997), it is the evocation of attentional factors at certain critical points 
during activation of higher level schemas which opposes error tendencies and keeps the 

error rate low. 

Schwartz and Buxbaum (1997) discussed two key assumptions of the Unified 
Hypothesis. The first key assumption is that damage to the movement engrams and/or 
the perceptual systems, or the semantic systems that input to the movement engrams 
would affect the ATS system by compromising its automatically. This lack of 
automaticity leads to greater dependence on attention and specifically on supervisory 
attention. Supervisory attention is evoked when automatic action routines are 
insufficient or inappropriate to complete the task at hand (Norman & Shallice, 1980, 
1986). Supervisory attention has been equated with working memory by Baddeley 
(1986). Schwartz and Buxbaum (1997) proposed that "for the patient with faulty 
access to gesture engrams or perceptual-semantic processing, successful performance 
of familiar, pragmatic action, depends more heavily on [attentional] control processes" 

(P- 19). 

The second key assumption of the Unified Hypothesis is that behavioral 
consequences of this increased dependency on supervisory attention/working memory 
depend upon a combination of the severity of damage to the ATS system and the status 
of the supervisory attention/working memory, itself. That is, a deficit in one 
component (activation of action schemas or attentional control systems) of the Unified 



38 



Hypothesis may not impact actions in natural contexts without some degree of damage 
to the other component. The authors argue that it is this combination of deficits that 
leads to action errors in natural contexts. That is, patients who have deficits in the 
automatic activation of action schemas will not evince action errors unless there is also 
a deficit in supervisory attention/ working memory and/or executive control processes. 
Conversely, patients with deficits in executive control processes will not evince action 
errors unless there are co-existing deficits in posterior processing systems which impact 
the automaticity of the action schemas. In addition, patients with a cortical dementia or 
diffuse head injury, may demonstrate the most serious errors of action during activities 
of daily living because of the severity of deficits in both the automatic activation of 
action schemas as well as executive control systems (Schwartz & Buxbaum, 1997). 
The Relationship Between Apraxia and Pragmatic Action 

It is possible that neither the model proposed by Rothi et al. (1991, 1997) or the 
Unified Hypothesis proposed by Schwartz and Buxbaum (1997) can independently 
account for all of the errors produced by brain-damaged patients during goal-directed 
activities of daily living (pragmatic action). In the following discussion, pragmatic 
action will be defined as the sequences of movements required to progress toward and 
obtain a definable goal. The goal may be directed toward common, everyday actions 
such as eating, or uncommon actions such as building a house (uncommon actions may 
vary from person to person depending upon life experiences). In contrast, movement is 
defined as changes in posture, place, or position which can occur within an action as 
well as independently. Actions and movements have been disambiguated to represent 
the notion that movements are the inherent motor aspect of performing actions {i.e., 



39 






movements are the final common denominator for all actions) and that actions are a 
series of movements arranged in hierarchically organized schemas according to the end 
goal. Using these definitions of pragmatic action and movements, the Rothi et al. 
(1991, 1997) Cognitive Neuropsychological Model of Limb Praxis and Apraxia 
encompasses aspects related to the planning, organization, production and 
comprehension of discreet movements (hereafter referred to simply as "movements") 
while the Schwartz and Buxbaum (1997) Unified Hypothesis covers aspects related to 
the planning, organization, production, and comprehension of actions which 
incorporate discreet movements (hereafter referred to simply as "actions") and it is the 
relationship or interaction between these two theories that is crucial for the 
understanding of pragmatic action . In the following discussion, a relationship between 
movements and actions will be proposed which will then be used as a foundation for 
examining the production of errors during goal-directed activities of daily living. 
It is proposed that higher level action schemas discussed by Schwartz and 
Buxbaum (1997) access lower level schemas of movement organization found in the 
action output lexicon as discussed by Rothi et al. (1991, 1997) (Figure 1-9). The action 
output lexicon, hereafter referred to as praxicon as suggested by Heilman and Rothi 
(1997), in turn, accesses the innervatory patterns and the motor system in that order, for 
production of the movement (Rothi et al, 1991, 1997) (Figure 1-10). Within the high 
level schemas, information about object, tool, sequence, and other aspects of action are 
organized hierarchically into plans or scripts according to specific goals. It is also 
proposed that the high level action schemas also contain attributes of movement 
planning but under normal circumstances, the praxicon takes precedence. 






40 



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According to Schwartz et al. (1991, 1993, 1995, 1997) there may be many 
different levels of schema. That is, for one set of goal-directed action sequences, a 
particular schema may be organized as a "lower level schema" whereas in a different 
set, the same schema may be organized as a "higher level schema." In fact, it is 
possible that schemas may be organized in such as way that a lower level schema may 
be included in a higher level schema which is included in an even higher level schema 
and etc. In order to conceptualize this framework it is proposed that within the high 
level schematic system, information is stored in a distributed network framework and is 
therefore subject to assumptions associated with parallel-distributed-processing (PDP) 
models as described by Rumelhart and McClellan (1986). For example, three 
assumptions about connections between nodes that are frequently activated together are 
1) as the number of times of activation increases, the strength of the connection will 
also increase, 2) as strength increases the nodes are activated faster, and 3) the stronger 
the connections, the less likely they are to be degraded (Rumelhart & McClellan, 1986; 
Nadeau. 1994). The corresponding assumptions for the high level schematic system are 
1) stronger associations occur between information/schemas that are frequently 
activated together, 2) the schemas with the most activation become learned, routine 
actions and eventually become automatic, and 3) the schemas for common, learned 
actions are less likely to show deficits following brain damage due to "a great deal of 
redundancy [interconnectiveness] in the neural systems responsible for pragmatic 
action" (Schwartz & Buxbaum, 1997, p2). 

Norman and Shallice (1980, 1986) and Schwartz and Buxbaum (1997) 
discussed the role of supervisory attention/working memory (SA/WM) in the 






43 



production of actions. The role of SA/WM was to monitor actions and step in as 
needed during their production so errors would be circumvented. SA/WM also 
contributed the most resources to monitor novel actions, a lesser amount of resources to 
monitor non-routine actions, and the least amount of resources to monitor routine or 
learned actions which could eventually become automatic and be produced correctly 
without attentional resources (Schwartz & Buxbaum (1997). To account for these 
different aspects of actions, the connection between executive functions (as defined by 
Schwartz et al, 1991, 1993, 1995) and the output praxicon has been divided into four 
routes, each requiring different amounts of attentional resources (Figure 1-11). It is 
proposed that the route for production of automatic actions (those learned, routine 
actions that are performed in context using actual tools and objects) bypasses attention 
and accesses the output praxicon directly because the combined effects of the natural 
context, tools, and objects may be enough information to activate that part of the motor 
system specialized for overlearned, automatic movements (Paillard, 1982, Marsden, 
1982, Rapscak et al, 1993, Schwartz & Buxbaum, 1997) The routes for routine and 
non-routine actions both access the output praxicon but non-routine actions require 
greater attentional resources than routine actions for accurate production. Additionally, 
the route for novel actions accesses the innervatory patterns rather than the output 
praxicon because by definition, "novel" movements have not been produced 
previously and, therefore, would not have engrams represented in the output praxicon. 
Novel actions also require more attentional resources than either routine or non-routine 
actions. 



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Because the output praxicon receives information from the semantic system and the 
semantic system is accessed by the perceptual systems, both systems (semantic and 
perceptual) have been added to the model according to Rothi et al, (1991, 1997) in 
Figure 1-12 and 1-13. Additionally, it is proposed that the executive functions in the 
high level schematic system also communicates with the semantic system in order to 
establish semantic relationships and interactions among related schemas. To 
accommodate this communication, the semantic system has been divided into two parts 
with one part connecting to the output praxicon and another part with connections to 
and from executive functions. This division is not without debate, however, because 
one could argue that the semantic system which communicates with the low level 
movement schemas contains procedural information about tools and objects while the 
semantic system which communicates with the high level action schemas contains 
episodic information about action sequences. 

Schwartz and Buxbaum (1997) and Reason (1979, 1984) also discussed visual, 
auditory, and tactile perceptual systems as important input systems for online 
monitoring and feedback to ensure correct action production. To accommodate these 
reports, the perceptual system has been added to the high level action schema system 
with input connections to executive functions (the planning and organization of action 
schemas) and attention (Supervisory attention/working memory) in Figure 1-14. The 
perceptual systems, therefore, send information to both the low (movement) and high 
(action) schema systems. 

In summary, the proposed relationship between apraxia and pragmatic action 
described above separated the components of pragmatic action into low and high level 



46 




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schematic systems. The low level system targets planning, organization, production, 
and comprehension of movement and movement sequences which are the final 
common denominator of actions. The high level system includes planning, 
organization, production, and comprehension of actions and action sequences 
(schemas) which originate in the complex schematic system of executive functions and 
require attentional monitoring for correct production. The final common denominator 
for both actions and movements is the praxis system, specifically, the output praxicon, 
innervatory patterns, and motor system. 
Predictions of the Proposed Relationship Between Movem ents and Actions 

Based on the above description of the relationship between action schemas and 
movements, the following predictions are made. First, pragmatic action can be divided 
into two levels, a high level for actions and a low level for movements, with the final 
common denominator of production through the output praxicon. Following this 
prediction, there should be dissociations between the ability to plan and organize 
actions (which occurs at the high level) from the ability to plan and organize 
movements (at the low level). A deficit in the ability to plan, organize, and execute 
actions has been documented by Mayer et al. (1990), Schwartz et al. (1991, 1993, 
1995), and Schwartz and Buxbaum (1997) who studied patients with generalized brain 
damage from closed head injury and labeled the deficit frontal apraxia, and Sirigu, 
Zalla, Pillon, Grafman, Agid, and Dubois (1995, 1996), and Sirigu, Zalla, Pillon, 
Grafman, Dubois, and Agid (1996) who studied patients with frontal lobe damage and 
labeled the deficits as problems in managerial knowledge. However, Mayer et al. 
(1990), Schwartz et al. (1991, 1993, 1995), Schwartz and Buxbaum (1997) and Sirigu 






50 



et al. (1995, 1996, in press) did not test for apraxia, a deficit in the ability to plan, 
organize and execute movements. Ideomotor apraxia is well documented in the 
literature by Liepmann (1900/1977, 1905b/1980b, 1907/1980c, 1920), DeRenzi (1985), 
DeRenzi et al. (1966, 1982), Heilman et al. (1982), Rothi et al. (1985), Rothi and 
Heilman, (1985), Sirigu, Cohen, Duhamel, Pillon, Dubois, and Agid (1995), and 
Foundas et al. (1995). Ideomotor apraxia has been localized to damage in the dominant 
hemisphere (Liepmann & Maas, 1907; Geschwind, 1965; Heilman, 1979; and Poizner, 
Meriens, Clark, Macauley, Rothi, & Heilman, 1997) and specifically to posterior 
parietal cortex (Heilman, 1979; Freund, 1991 ; and Poizner et al, 1997). However, the 
focus of the above studies was on either high level action planning and organization 
abilities, without documenting presence or absence of low level factors, or vice versa- 
focus on low level action planning and organization abilities without documenting 
presence or absence of high level factors. 

Only one study to date has examined both low and high level schematic 
functions within the same patient. Schwartz et al. (1995) examined action planning and 
praxis in a patient, J.K., who suffered brain damage as the result of closed head injury. 
Results indicated that J.K. evinced significant deficits in both the planning and 
organization of actions and the planning and organization of movements. 
Unfortunately, due to the extent of brain damage (lesions in right frontal lobe, bilateral 
temporo-parietal lobe, and left occipital lobe) brain-behavior relationships could not be 
made. Further studies are needed to document whether patients with impaired 
planning and organization of actions have spared planning and organization of 
movements and vise versa. However, because the supplementary motor area (SMA) 



51 



located in the prefrontal gyrus has been implicated in the production of learned 
movements (Heilman, 1979) and it is proposed that the production of movements is the 
final common pathway for all actions, researchers must be strict as to location of lesion 
(i.e., with/without damage to SMA in patients with frontal lobe lesions) and in modality 
of task (i.e., test action planning and organization through pictures and not through 
actual production for patients with ideomotor apraxia as the ideomotor apraxia will 
affect production) when selecting subjects and experimental tasks. It should also be 
noted that due to the proposal that the output praxicon is the final common pathway for 
production of actions, patients with ideomotor apraxia have the potential to be impaired 
in production across tasks - clinical and environmental. This impairment across tasks 
has been documented experimentally by Foundas et al. (1995) and through case reports 
by Jacobs, Macauley, Adair, Gold, Rothi, and Heilman (1995) and Sirigu et al. (1995). 

A second prediction states that deficits in action semantics should affect the 
functional use of tools within higher level schemas (in context or part of a goal-directed 
schema) as well as within lower level schemas (out of context or independent of goal- 
directed schema). Ochipa et al. (1989) reported a left-handed patient with a right 
hemisphere lesion who demonstrated deficits in the functional use of tools across high 
and low level tasks. High level tasks included eating a meal and low level tasks 
included pantomiming to command (e.g., show me how you use scissors). Results 
indicated that the patient was impaired in all tasks in which the functional relationship 
between tool and object were important. It should be noted, however, that Ochipa et al. 
(1989) labeled the patient's disorder "ideational apraxia" and defined it as a loss of 
conceptual knowledge related to tool use. Raymer (1992) and Raymer and Ochipa 



52 



(1997), labeled this disorder "conceptual apraxia" which better describes this global 
impairment of both low and high level schema functions. 

A third prediction states that errors of action produced by non brain-damaged 
people should relate to high level schema problems, the planning and organization of 
actions, and not low level schema problems, the planning and organization of 
movements. "Normal" people have intact praxis systems and should therefore produce 
skilled movements accurately. However, the correct production of actions depends 
upon the mediation of supervisory attention/working memory and if a person is not 
"paying enough attention" or becomes distracted during the task at hand, a different 
action, correctly produced, may be performed. Reason (1979, 1984, 1990) and Reason 
and Mycielska (1982) studied human error and lapses of attention in everyday life. 
They report that normal people produce errors of omission, addition, anticipation, 
perseveration, capture, exchange, and substitution all of which occur within action 
schemas and not within movements. For example, an error of capture occurred when a 
lady went to the bathroom intending to brush her hair but she picked up the toothbrush 
and began to brush her teeth. This lady did not pick up the toothbrush and brush her 
hair or perform any action out of sequence for that particular schema, she merely 
performed the wrong action schema for her intention which is a high level schematic 
system error. Schwartz and Buxbaum (1997) classified the errors produced by brain 
damaged patients during six daily activities, including making toast and wrapping a 
present, using Reason's (1979, 1984) classification system. Schwartz and Buxbaum 
(1997) reported that the brain damaged patients produced errors not only from the 
categories described by Reason (1979, 1984) but also in four categories not described 



53 



by Reason (1979, 1984) - grasp/spatial misorientation, spatial misestimation, tool 
omission, and quality of movement. These four error types are hypothetically related to 
the low level schematic system and would be predicted in patients with damage to the 
praxis system by this model. Unfortunately, Schwartz and Buxbaum's (1997) patients 
had heterogeneous etiologies and were not tested for conceptual or ideomotor apraxia 
and therefore, direct evidence to support this prediction can not be obtained. Further 
studies are necessary to examine the types of errors produced by brain damaged 
patients and to establish a classification system using the framework of the proposed 
model. 
Classification of Action Errors 

The types of errors described by Foundas et al. (1995), Ochipa et al. (1989), 
Mayer et al. (1990), Schwartz et al. (1991, 1993, 1995), Singula/. (1995, 1996) and 
Schwartz and Buxbaum (1997) can be divided into two categories based upon the low 
(movement) and high (action) schema systems proposed by the relationship described 
above (Figure 1-14). That is, error types that reflect deficits in the praxis production 
systems (Rothi et al., 1991) would make up low level schematic system errors while 
error types that reflect deficits in the planning and organization of action in the 
executive function and attentional control mechanisms (Schwartz & Buxbaum, 1997) 
would make up high level schematic errors. However, some types of errors could be 
produced by both a high and a low level schema deficit. For example, the misuse of a 
fork to stir tea could be explained by a deficit in the praxis conceptual system - a low 
level schema error - or by a deficit in attentional control of the action sequences (the 
patient had just finished using a fork to eat meat and did not switch tools before stirring 



54 



tea) - a high level schema error. Other types of errors such as the body part as tool 
errors reported by Rothi et al. (1991) can only be explained by a low level schema 

deficit. 

However, no study to date has measured deficits associated with low and high 
level schemas within the same group of patients in order to tease out which action 
errors are associated with which type of deficit. Foundas et al. (1995) and Ochipa et al. 
(1989) tested the praxis production and conceptual systems (low level schema) while 
Mayer et al, (1990), Schwartz et al. , (1991, 1993), Sirigu et al. (1995, 1997), and 
Schwartz and Buxbaum (1997) tested executive function, managerial knowledge, and 
planning/ organizational abilities (higher level schema). Schwartz et al., (1995) 
measured both low and high level schema abilities in a patient with diffuse brain 
damage after closed head injury. However, an MRI of this patient showed focal lesions 
in the left occipitoparietal area, right frontal area, and bilateral temporal areas which 
negated any attempt to establish brain-behavior relationships and examine the 
underlying nature of action errors. 

Foundas et al. (1995) proposed that the errors produced by the experimental 
subjects in their study could be divided into two groups - production and conceptual. 
Production errors consisted of movement, timing, and sequence errors and conceptual 
errors consisted of misuse and mis-selection of a tool for the intended task. However, 
as discussed above, production and conceptual errors can occur as the result of deficits 
in low and/or high level schema systems. Production errors have been associated with 
ideomotor apraxia resulting from discrete lesions of the dominant left hemisphere 
(Foundas et al., 1995) as well as executive function disorders from closed head injury 









55 



(Schwartz et al, 1995) and conceptual errors have been associated with ideational/ 
conceptual apraxia resulting from discrete lesions of the dominant hemisphere (Ochipa 
et al, 1989) as well as resulting from generalized brain damage from closed head injury 
(Schwartz et al, 1995). However, all of the experimental subjects in the Foundas et al, 
(1995) study had unilateral (dominant hemisphere) brain lesions resulting from single 
strokes. Even though it would be easy to propose that the errors produced by these 
subjects originated in the low level schema system, these subjects also evinced deficits 
in the overall organization of meal planning, a high level schema system. However, 
Foundas et al (1995) did not test for presence of conceptual apraxia or executive 
function (planning/ organizational) deficits that may explain the presence of high level 
schema errors. Therefore, although Foundas et al. (1995) argued that the errors 
produced by the experimental subjects strongly correlated with ideomotor apraxia, it is 
not known whether conceptual or executive disorders also influenced the production of 
action errors within these subjects. 

Each of the above studies (Foundas et al, 1995; Ochipa et al, 1989; Mayer et 
al, 1990; Schwartz et al, 1991, 1993, 1995; Sirigu et al. 1995, 1996, in press; and 
Schwartz & Buxbaum, 1997) documents the presence of action errors in activities of 
daily living. However, each study evaluated subjects with different etiologies of brain 
damage (i.e., traumatic brain injury versus stroke) using different evaluation criteria 
and asking different research hypotheses as to the nature of these action errors. As a 
result, the nature of the movement and action errors produced by brain damaged 
patients observed in natural contexts remains unclear. It is possible that by examining 
deficits associated with both low and high level schemas in a homogeneous group of 



56 



subjects within a well controlled study that the nature of action deficits in activities of 
daily living can be better understood and explained. 

Statement of the Problem 
While the presence of action and movement errors in natural contexts has been 
described by several research groups, the mechanism of these action errors has not been 
determined. In the above discussion, four explanations that may account for these 
errors in natural contexts were described. The first proposes that movement and action 
errors in natural contexts may be the result of an executive disorder of planning and 
organization (Mayer tf ai, 1990; Schwartz et ai, 1991, 1993, 1995; Sirigu etal, 1995, 
1996; and Schwartz & Buxbaum, 1997), a high level schematic system function 
according to the proposed relationship between movements and actions. The second 
proposal states that action errors in natural contexts may be the result of an impaired 
supervisory attention/ working memory (Schwartz et at, 1995; Schwartz & Buxbaum, 
1997) a high level schematic system function according to the proposed relationship 
between movements and actions. The third proposal states that action errors in natural 
contexts may be the result of a deficit in action semantics or tool-function-object 
knowledge (Ochipa et al, 1989, 1992) a function that implicates both high and low 
level schematic system function according to the proposed relationship between 
movements and actions. The fourth proposal states that the action errors in natural 
contexts may be the result of ideomotor apraxia, an impairment in the production of 
learned, skilled movements (Foundas et al, 1995); a low level schematic system 
function according to the proposed relationship between movements and actions. 



57 



Previous studies of action errors compared the performance of left brain 
damaged patients with normal controls (Foundas et al, 1995), compared patients with 
heterogeneous etiologies with normal controls (Sirigu et al 1995, 1996; Schwartz & 
Buxbaum 1997), or were single case studies (Ochipa et al, 1989; Mayer et al, 1990; 
Schwartz et al, 1991, 1993, 1995). In fact, only three subjects, presented as single case 
studies, form the basis of the Mayer et al, 1990, and Schwartz et al, 1991, 1993, and 
1995 studies. The proposed cognitive neuropsychological model of pragmatic action 
predicts that action errors can occur as the result of low level schematic system 
impairment as well as high level schematic system impairment, both of which can be 
associated with unilateral lesions of the dominant hemisphere. However, no study to 
date has examined the presence of action errors in patients with unilateral lesions of the 
nondominant (right) hemisphere in right-handed individuals. Due to the heterogeneous 
nature of brain damage in previous studies as well as the lack of testing in both the low 
and high level schema system, conclusions about brain-behavior relationships and the 
nature of action errors can not be made. Therefore, studies are needed that 1) include 
subjects with unilateral lesions of the nondominant (right) hemisphere and examine 
both low and high level schema function; and 2) use a consistent error classification 
system to score the subjects' performance in natural contexts which incorporates 
scoring systems described thus far in the literature - by Reason (1979, 1984), Foundas 
et al (1995), Schwartz et al (1995), and Schwartz & Buxbaum, (1997); and 3) 
compare subjects with brain damage limited to one hemisphere (right or left) from a 
single event rather than generalized brain damage resulting from trauma in order to 
examine brain-behavior relationships more clearly. 



58 



The purpose of this study, therefore, is to examine the nature (low versus high 
level schema system functions) of action errors produced during an activity of daily 
living in the natural environment in patients with left or right hemisphere brain damage 
as well as neurologically normal control subjects. The following specific questions will 

be addressed: 

1 . Does brain damage in either hemisphere result in production of 
action errors in the natural environment or are action errors specific to left 
hemisphere brain damaged patients? 

The Foundas et al. (1995) study documented production of action errors by ten 

left hemisphere damaged patients in the natural context of eating a meal. Other studies 

described action errors produced by single subjects with either right hemisphere 

damage (in a left-handed patient) or closed head injury (Ochipa etal., 1989; Mayer et 

al, 1990; Schwartz et al. , 1991, 1993, 1995; and Schwartz & Buxbaum, 1997). 

Because only the left hemisphere damaged patients were experimentally studied, it is 

not known whether the action errors described in the above studies are specific to 

patients with lesions of the dominant hemisphere or can be found in right hemisphere 

damaged patients as well. Using the proposed relationship between apraxia and 

pragmatic action, it is proposed that patients with dominant (left) hemisphere brain 

damage produce action errors consistent with both low and high level schema system 

functions while patients with lesions of the nondominant (right) hemisphere produce 

action errors consistent with high level schema system function only. This difference is 

due to the bilateral representation of executive functions and the lateralized 

representation of the visuokinesthetic engrams for learned movement to the left 

hemisphere. This difference would predict that patients with left hemisphere damage 



59 



have more opportunity for errors and may therefore produce more errors than patients 
with right hemisphere lesions. According to the proposed model, patients with lesions 
of the nondominant right hemisphere may evince action errors as a result of executive 
system function impairment (deficits in the planning, and organization of actions) as 
well as from attention system impairment as these are both represented bilaterally and 
impairment of one hemisphere may result in deficits in these systems. The errors 
resulting from attentional system impairment may include spatial errors resulting from 
neglect which has been described as a disorder of attention by Brain (1941), Zangwill 
(1944), McFie, Piercy, and Zangwill (1950), Denny-Brown and Banker (1954), 
Heilman (1979), and Heilman, Watson, and Valenstein (1985). Heilman (1979) 
reported that some patients with neglect fail to eat from one side of their plate but have 
spared action plans for eating and use of tools during eating. The null hypothesis of no 
difference in number of action errors produced while eating a meal between the groups 
(left hemisphere damaged subjects, right hemisphere damaged subjects, and controls) 

will be tested. 

2a. Does presence of deficits in 

1 . production of learned skilled movements, 

2. conceptual knowledge of tool-function relationships, 

3. action planning and organization, and 

4. supervisory attention/working memory 

predict production of action errors in the natural environment? 

2b. And if so, to what extent does each type of deficit (low level system 
deficits- 1 and 2 above and high level system deficits-3 and 4 above) predict 
type of error (including misuse, mis-selection, external configuration, internal 
configuration, timing, quantity, sequence [omission, addition, sequence], 
exchange, substitution, movement, and body part as tool)? 

Deficits in conceptual knowledge of tool-function relationships and deficits in 

production of learned skilled movements are proposed to result from lateralized lesions 






60 



to the dominant (left) hemisphere in most right-handed people (Rothi & Heilman, 1985) 
and are hypothesized to be associated with low level schemas in the proposed 
relationship between movements and actions. Deficits in the planning and organization 
of actions and deficits in supervisory attention/working memory are proposed to result 
from left, right, and bilateral lesions as well as degenerative brain damage (Schwartz et 
ai, 1991, 1993, 1995) and are hypothesized to be associated with high level schemas in 
the proposed cognitive neuropsychological model of pragmatic action. As a result, all 
four deficits of higher cortical function described above have the potential to produce 
action errors in natural contexts. To examine the relationship between these disorders 
of higher cortical function and production of action errors in the environment, 
independent measures (non-context dependent) of each disorder will be correlated with 
total number of action errors produced in the experimental measures (context- 
dependent). The null hypothesis of no significant correlation between any one 
independent measure of higher cortical function and number of total action errors 
produced during the context dependent activities of daily living will be tested. 

In addition, it is hypothesized that tool and nontool errors will be produced to 
different degrees by patients depending on the type and severity of higher cortical 
function deficit. That is, patients with deficits in the praxis production and conceptual 
systems (low level movement schema) may produce more tool errors (misuse, mis- 
selection, internal configuration, external configuration, quantity of food on a utensil, 
movement associate with the tool, and body part as tool) than patients without a deficit 
in the praxis production and/or conceptual system. Hypothetically, the number of tool 
errors produced should reflect the severity of the underlying deficit(s). Patients with a 



61 



deficit in the planning and organization of actions and/or supervisory attention/working 
memory (high level schema) may produce more nontool errors (exchange, substitution, 
sequence, omission, addition, and timing,) than patients without a deficit in the 
planning and organization of actions and/or supervisory attention/working memory. 
Although these patients may also show tool errors of misuse and mis-selection which 
could arise from high level schema deficits, these patients should not evince tool errors 
of internal configuration, external configuration, quantity, and body part as tool without 
a concomitant deficit in the praxis system. 

As a result of the action error classification system described above, it is 
proposed that the errors reported by Foundas et al. (1995) as resulting from ideomotor 
apraxia or production disorders, may also have been influenced to a certain extent by 
high level schema deficits and that errors reported by Mayer et al. (1990), Sirigu et al. 
(1995a, 1995b, 1996), and Schwartz et al. (1991, 1993, 1995) as resulting from 
disorders of action planning and organization and/or supervisory attention/working 
memory may also have been influenced by production and conceptual disorders. 
However, it is not known which of the four disorders (praxis production, praxis 
conceptual, action planning/ organization, and supervisory attention/working memory) 
is most influential in inducing action errors in natural contexts or if all four disorders 
are equally influential. To answer this question, independent measures of the praxis 
production system, praxis conceptual system, action planning/organization, and 
supervisory attention/working memory will be correlated with frequency of each type 
and classification of error produced during the experimental activities of daily living. 



62 



The null hypothesis of no significant correlation between any one independent measure 
and number of action errors within one type/classification will be tested. 



CHAPTER TWO 
METHODS 



Some patients with brain damage produce action errors during activities of daily 
living (Mayer et al, 1990; Schwartz et al, 1991, 1993, 1995; Schwartz & Buxbaum, 
1997; Ochipa et al, 1989; Foundas et al, 1995). Investigators in recent research reports 
have examined the planning, organization, and production of these action errors through 
different theoretical models with different inherent assumptions and predictions, using 
different research hypotheses and evaluation criteria, and included subjects with 
heterogeneous etiologies of brain damage (Mayer et al, 1990; Schwartz et al, 1991, 
1993, 1995; Schwartz & Buxbaum, 1997; Sirigu etal, 1995, 1995, 1996, in press; 
Ochipa et al, 1989; Foundas et al, 1995). The current study describes a proposed 
relationship between apraxia and pragmatic action which serves as a framework for the 
examination of the nature of movement and action errors produced by patients with 
unilateral left or right hemisphere brain damage as well as matched normal control 
subjects. 

Subjects 

Three subject groups (two experimental groups and one control group) 

participated in this study. The first experimental group consisted of patients with left 

hemisphere strokes (LBD) and the second experimental group consisted of patients with 

right hemisphere strokes (RBD). All experimental subjects were at least one month post 

onset of their stroke, were right-handed, and native English speakers. None had a history 

63 



64 
of previous neurological disease. The experimental subjects were at least one month post 
onset of a unilateral CVA (from a single event) as documented by CT/MRI scan and were 
identified and recruited through the following sources: Veterans Affairs Medical Center, 
W. A. Shands Teaching Hospital, and UpReach Rehabilitation Center, Gainesville, 
Florida; Sacred Heart Medical Center, Deaconess Medical Center, St. Luke's 
Rehabilitation Center, and University Programs in Communication Disorders Speech and 
Hearing Clinic, Spokane, Washington. CT/MRI studies done at least two weeks post- 
stroke were obtained for each experimental subject and reviewed by a neurologist. The 
neurologist classified the lesions as either right or left as defined by relationship of lesion 
to longitudinal fissure. The lesion locations were used to classify the experimental 
subjects into left-hemisphere or right-hemisphere damaged groups. 

The LBD experimental group included 20 subjects whose ages ranged from 32 to 
79 (M = 60.2; SD = 13.50). Educational level ranged from 3 to 16 years (M = 1 1.85; SD 
■ 3.25). Time post stroke varied from one month to 261 months (M = 41.45; SD = 
65.28). Descriptive information for these LBD subjects is provided in Table 2-1. 

The RBD experimental group included 10 subjects whose ages ranged from 54 to 
77 (M = 64.2; SD = 8.1 1). Educational level ranged from 8 to 16 years (M = 12.60; SD = 
2.46). Time post stroke varied from one month to 40 months (M = 1 1.3; SD = 15.47). 
Descriptive information for these RBD subjects is provided in Table 2-2. 



65 



Table 2-1 LBD Subject Identification 



Subject 


Sex 


Age 


Education 


MPO* 




LI 


M 


63 


9 


28 




L2 


M 


79 


3 


53 




L3 


M 


64 


4 


25 




L4 


M 


70 


15 


84 




L5 


M 


62 


12 


2 




L6 


M 


79 


14 


168 




L7 


M 


69 


12 


67 




L8 


M 


62 


12 


261 




L9 


M 


77 


16 


19 




L10 


F 


45 


15 


16 




Lll 


F 


35 


12 


37 




L12 


M 


55 


12 


28 




L13 


M 


65 


12 


1 




L14 


F 


58 


13 


4 




L15 


F 


52 


14 


17 




L16 


F 


55 


12 


1 




L17 


F 


78 


12 


1 




L18 


F 


56 


12 


1 




L19 


F 


32 


12 


8 




L20 


M 


48 


14 


8 





*MPO - months post-onset 






66 



Table 2-2 RBD Subject Identification 



Subject 


Sex 


Age 


Education 


MPO* 




Rl 


M 


76 


13 


40 




R2 


M 


58 


10 


2 




R3 


M 


59 


16 


27 




R4 


M 


77 


13 


5 




R5 


M 


62 


12 


4 




R6 


M 


73 


16 






R7 


F 


54 


8 






R8 


F 


61 


14 






R9 


M 


62 


12 






RIO 


M 


60 


12 


31 





*MPO - months post-onset 



The control subject group consisted of 10 neurologically intact community 
volunteers from Gainesville and Bradenton, Florida, and Spokane, Washington. All 
control subjects were also right-handed and native English speakers. Their ages ranged 
from 46 to 76 years (M = 64.1; SD = 8.62). Educational levels ranged from 10 to 16 
years (M = 12.6; SD = 1.84). Descriptive information regarding the control subjects is 
provided in Table 2-3. 






67 






Table 2-3 Control Subject Identification 



Subject 


Sex 


Age 


Education 


CI 


M 


69 


13 


C2 


M 


71 


13 


C3 


M 


63 


12 


C4 


M 


59 


16 


C5 


F 


69 


12 


C6 


F 


63 


10 


C7 


M 


68 


14 


C8 


M 


57 


14 


C9 


M 


76 


10 


CIO 


F 


46 


12 



Materials and Methods 
The description of the experimental procedures that follows is divided into two 
sections, each containing a description of the materials, methods of presentation, and 
scoring procedures relevant to each measure. The first section, entitled evaluation of 
independent variables describes tests designed to measure the deficits associated with 
inpairment in action planning and organization (i.e., "frontal apraxia," a high level 
schema deficit), deficits in the production of learned, skilled movements (i.e., ideomotor 
apraxia, a low level schema deficit), deficits in conceptual knowledge of tool-object- 
function relationships (i.e., conceptual apraxia a low and/or high level schema deficit), 
and deficits in supervisory attention/working memory (high level schema deficit). In 



68 

addition, tests of language abilities and presence of neglect are described. Results of the 
tests of language and neglect were not used to directly answer the stated research 
questions. Rather, due to the co-occurrence of aphasia and apraxia in left hemisphere 
damaged patients and the occurrence of neglect in right hemisphere damaged patients, 
these variables must be systematically measured in order to assist in the interpretation of 
the results. The second section, entitled evaluation of dependent variables describes a 
task designed to measure production of movement and action errors in an activity of daily 

living. 

All subjects were administered the same battery of tests. Testing occurred within 
one day or across a two-day period. The order of presentation of all tests was 
randomized across subjects. 
Evaluation of Independent Variables. 
Disorders of action planning and organization 

Materials . The Tower of London task (TOL, Shallice, 1982; Krikorian, Bartok, & 
Gay, 1994) was given to evaluate deficits in the ability to plan and organize actions 
associated with "frontal apraxia." The TOL consists of three pegs of different lengths 
mounted on a strip of board and three colored balls (red, green, and blue). The balls have 
holes drilled through them so they can be placed on the pegs. The left peg held all three 
balls, the middle peg held two balls, and the right peg held one ball. 

Methods . The standardized administration procedures described by Krikorian et 
al. (1994) were used in this study. The balls were placed in a standard initial position 
(red ball on top of green ball on left peg and blue ball on middle peg) and the subject was 



69 

asked to manipulate the balls on the pegs to reproduce a pictured end state (Figure 2-1). 
The subject performed twelve trials of increasing difficulty. A problem was correctly 
solved when the end state was achieved in the prescribed number of moves. The subject 
had three attempts to solve each trial. 

Scoring . The standardized scoring procedures described by Krikorian et al. 
(1994) were used in this study. The subject received three points if the trial was solved 
correctly on the first attempt; two points if solved on the second attempt; one point if 
solved on the third attempt; and zero points if not solved by the third attempt. The 
examiner scored each subjects' performance online according to the above mentioned 
criteria and percent correct was calculated by dividing the number of points accumulated 
by the total number of points possible. 
Disorders of learned, skilled movements 

Materials . The Randomized Form A (RFA) and Randomized Form B (RFB) 
versions of the Gesture to Command subtest of the Florida Apraxia Battery: Experimental 
Edition (Appendices A & B, Rothi, Raymer, Ochipa, Maher, Greenwald, & Heilman, 
1992) were given to evaluate presence and severity of disorders of learned, skilled 
movements associated with ideomotor apraxia. The Gesture To Command subtest 
consists of 30 commands which elicit transitive or intransitive gestures. Transitive 
gestures {e.g., show me how you use a hammer) involve tool knowledge and 
demonstration of how one uses tools. Intransitive gestures {e.g., show me how you 
would salute) do not involve tool knowledge and have been defined as emblems by 
Lemay, David, and Thomas (1989). (See Appendix A for copies of the RFA and RFB). 



70 




Initital State 




End State - 3 moves 




End State - 5 moves 



Figure 2-1. The Tower of London (from Krikorian, Bartok, & Gay, 1994). 



71 



To control for the possible effects of hand used to gesture, Raymer, Maher, 
Macauley, Foundas, Rothi, and Heilman (1997) studied the performance of 16 
neurologically normal, right handed control subjects on this Gesture to Command subtest 
looking at the influence of hand used. They divided the 16 subjects into four groups and 
administered the RFA or RFB counterbalancing hand used to gesture in the following 
manner: Group 1 was administered RFA and gestured all items with the right hand 
followed by all items with the left hand; Group 2 was administered RFA with the left 
hand used first; Group 3 was administered RFB with the right hand used first; and Group 
4 was administered RFB with the left hand used first. The tapes were then scored 
pass/fail by two raters with at least two year's experience in scoring gesture production 
using the Rothi, Mack, Verfaellie, and Brown (1988) error pattern analysis. Results 
indicated that there was no significant difference in the performance of the right and left 
hands by control subjects with no history of neurological disease when producing 
gestures to command (Raymer et ah, 1997). 

Methods . Each subject was administered either the RFA or RFB using the 
instructions written at the top of each score sheet (See Appendix A). The RFA and RFB 
were alternated across subjects with half receiving RFA and half receiving RFB. To 
control for possible effects of hemiparesis, the experimental subjects produced the 
gestures using their ipsilesional hand and five of the ten control subjects were asked to 
gesture using their non-dominant left hand. The subjects were videotaped while 
performing these gestures. 



72 

Scoring . The videotapes were scored by two examiners familiar with ideomotor 
apraxia who underwent a training session similar to that described by Maher (1995). 
During the training sessions, the examiners were required to obtain at least 85% 
agreement with practice tapes before beginning to score the experimental tapes. The 
scoring system followed the error pattern analysis described by Rothi et al. (1988). Each 
gesture was given a pass/fail rating and percent correct was calculated. 

Inter-rater reliability was calculated by having the raters score four videotapes 
twice and calculating percent agreement across the two sessions. Intra-rater reliability 
was calculated by calculating percent agreement between the two scorers on 20% of the 
videotapes. 
Disorders of tool-obi ect-function knowledge 

Materials . A revised version of the Tool-Object Matching Test (TOM) described 
by Ochipa et al. (1989) was given to evaluate deficits in tool-function-object knowledge 
associated with ideational/conceptual apraxia (Appendix B). The original version of the 
Tool-Object Matching Task described by Ochipa et al. (1989) used randomly generated 
tools as foils. The revised version used the same foil tools for each trial across subjects. 
The foil tools were drawn from the possible correct tool choices for the other trials and all 
tools were used three times - once as a correct answer and twice as foils (except for 
hammer which is a correct answer twice and used as a foil four times). 

Methods . Each subject was presented with a partially completed task {e.g. a 
partially sawed board) and an array of three tools consisting of the target tool and two foil 
tools {e.g. a hammer, saw, and pencil). The subject was asked to select the appropriate 



73 
tool to complete the task according to the instructions written at the top of the score sheet 

(Appendix B). 

Scoring . The examiner scored the subject's responses online using a binomial, 
pass/fail criteria and percent correct responses was calculated. 
Disorders of supervisory attention /working memory 

Materials . The Trailmaking Test - Parts A & B (Reitan, 1944) was used to 
evaluate deficits in supervisory attention/working memory. The Trailmaking Tests - 
Parts A & B ("Trails A & B") are standardized neuropsychological measures that are 
sensitive to brain damage. Good performance on Trails A & B depends upon attention to 
task and working memory with strong visual search and motor performance components. 
The standardized test sheets were used in this study. Trails A & B each consist of a 
single sheet of 8 1/2 x 1 1 white paper with the numbers 1 - 25 (Part A) and 25 numbers 
and letters (Part B) written in random order on the page. The numbers and letters are 
written in circles. 

Methods . Trails A & B were administered according to the standardized 

instructions by the examiner. 

Scoring . Trails A & B were scored according to the standardized instructions by 
the examiner. The time in seconds required for the subject to complete Part A and Part B 
were recorded separately and compared to normative data reported by Davies (1968) 
(Appendix C). 






74 
Disorders of language 

Materials . The Western Aphasia Battery ( WAB . Kertesz, 1981) was used to 
evaluate presence, type, and severity of aphasia. The WAB is a standardized test of 
acquired language disorders which enables the calculation of aphasia severity through an 
aphasia quotient (AQ) and determination of aphasia type through the WAB aphasia type 
taxonomy. The WAB is divided into four sections, spontaneous speech, comprehension, 
repetition, and naming, which test each aspect of verbal language skills in brain-injured 

patients. 

Methods . The WAB was administered according to the standardized instructions 
by the examiner, a certified speech-language pathologist with seven years experience 
working with neurologically based communication disorders. 

Scoring . The WAB was scored according to the standardized instructions by the 
examiner, a certified speech-language pathologist with seven years experience working 
with neurologically based communication disorders. An aphasia quotient reflecting 
aphasia severity score was calculated and type of aphasia was documented based upon 
the WAB aphasia taxonomy (Kertesz, 1981). 
Neglect 

Materials . A line bisection task was used to evaluate presence and severity of 
neglect. For the current study, three lines measuring eight, ten, and twelve inches in 
length were drawn horizontally across the middle of individual 1 1x14 pieces of paper 
using a thick black marker. 



75 
Methods . The examiner placed one of the pieces of "lined" paper described 
above horizontally on the table approximately eighteen inches in front of the subject with 
the middle of the line even with the subject's midsagittal plane. The subject was given a 
pen and asked to "mark the center of the line." This procedure was repeated for each of 
the three lines. The lines were given in random order to each subject. 

Scoring . The examiner scored the accuracy of the subject's mark by measuring 
the difference between the true middle of the line and the subject's mark. An average 
difference was calculated in centimeters. Presence of neglect was determined by a 
difference score of 10mm between the true midline and the subject's mark (Heilman, 
Watson, & Valenstein, 1985). Severity of neglect was determined by the magnitude of 
the average difference in that the greater the difference, the more severe the neglect. 
Evaluation of Dependent Variable-Eating a Meal. 

Materials . A meal consisting of a main course, at least one side dish, a dessert, 
and a beverage, and utensils such as a knife, fork, and spoon, were organized on a 
hospital tray according to standard etiquette rules. The food was placed on standard 
hospital plates with covers. Additionally, three foil items - a toothbrush, comb, and 
pencil, were also placed on the tray interspersed in random order with the utensils. The 
location of the foil items and the utensils were ipsilateral to side of lesion for the 
experimental subjects and counterbalanced across control subjects. Subjects who were 
inpatients received their meals in their hospital rooms from food service personnel during 
regular mealtimes. Subjects who were not inpatients obtained their meals through the 
hospital cafeteria using similar plates and covers as the inpatients and ate privately in a 






76 
research laboratory. Straws, condiments, and napkins were made available to each 
subject by the examiner. 

Methods . All subjects were videotaped while eating the meal. The videotaping 
was done using a Sharp videocamera set on a tripod approximately five feet in front of 
the subject. Taping was done on a TDK 120 minute videotape. The video camera was 
turned on just prior to the subject receiving their food and turned off after completion of 
the meal. The examiner was not in the room during the videotaping and nurses, spouses 
or significant others were instructed not to assist the subject in any way during the eating 
of the meal, unless specifically asked to do so by the subject. Conversation with family 
members during the meal was allowed to ensure a comfortable, natural environment. 
The examiner arranged the utensils and foil items on the tray after the meal had been 
delivered counterbalancing location (right or left) across control subjects. Subjects with 
specific dietary restrictions were accommodated through choice of meal. In order to 
control for possible effects of hemiparesis, an equal number of control subjects were 
asked to eat with their nondominant hand as experimental subjects who ate with their 
nondominant hand. 

Scoring . The mealtime videotapes were scored by two raters and a trainer at the 
same time but independently. The scoring was completed in a quiet room using a 20 inch 
viewing monitor and a Sony video player with slow motion and freeze frame capabilities. 
The trainer controlled the tape player for the raters but the raters were free to stop and 
rewind to view an action or series of actions as many times as necessary to ensure that all 
actions produced by the subjects were included. The raters were encouraged to consult a 



77 

list of error types given to them during the training time as often as needed during the 

scoring periods. No discussion was allowed with respect to the subject's performance 

and the raters were not able to see each other's or the trainer's score sheet. 

The scoring system described by Foundas et al. (1995) and the error classification 

system associated with the proposed relationship between apraxia and pragmatic action 

described in chapter one was used in this study. For the current study, an action was 

defined as a sequence of individual movements that result in the accomplishment of a 

definable goal and movements were defined as changes in place, position, or posture. 

For example, picking up the fork, piercing a piece of meat, and bringing the meat to the 

mouth would be three individual movements that make up one action. Each action was 

categorized as a tool or a nontool action. Examples of tool actions would be stirring tea 

with a spoon; eating a piece of meat with a fork ; and buttering a slice of bread with a 

knife. Examples of nontool actions would be placing the napkin in the lap; moving an 

empty plate to the side of the tray; and opening a packet of sugar. The raters were 

instructed to use a standard recording form to record the quadrant of the tray in which the 

action was initiated, which hand was used to perform the action, which tool and object 

were used, and which action was performed. The raters then determined if the action was 

correct or incorrect and if judged incorrect, the raters assigned an error type to the 

incorrect action. The error types are described below: 

Errors proposed to result from Low Level System Impairment: 

internal configuration : hand posture used to manipulate 

tool was incorrect (e.g., holding a spoon with a tightened fist). 



78 

external configuration : action produced was misplaced in space in absence of 
perceptual deficits (e.g., scooping with a spoon on the table beside the plate). 

body part as tool : action was produced using a body part as the tool (e.g., 
spreading butter on bread with index finger). 

timing : incorrect timing during a sequence of movements within one action (e.g. 
spreading butter on bread with pauses in between the knife movements) or 
between two actions (e.g., holding a spoonful of food close to the mouth while 
one is still chewing a previous bite). 

quantity : incorrect or inefficient amount of food is taken to the mouth (e.g., 
putting too much or too little mashed potatoes on a spoon which is then 
brought to the mouth). 

movement : movement produced was inaccurate or incorrect (e.g., using wrist 
motion rather than shoulder motion) 

Errors proposed to result from high level system impairment: 

sequence : sequence of actions was incorrect (e.g., stirring tea before 
adding the sugar) 

omission : omitting one action from a sequence of actions (e.g., putting 
sugar in tea and not stirring it at all). 

addition : adding an additional action during a sequence of actions (e.g. 
putting sugar in tea and eating a bite of food before stirring the tea). 

Errors proposed to result from high and/or low level system impairment: 

misuse : action (movement) produced was incorrect for chosen tool (e.g. , stirring 
with a knife) (See Figure 1-7.) 

mis-selection : action (movement) produced was correct for the chosen tool but 
not for the goal with the object (e.g., using a fork to eat ice cream) (See Figure 1- 
7.) 



It was possible for one action to be judged as represented by more than one error type 
during the scoring procedure. 



79 



Actions over the entire meal were recorded and scored and the following 
calculations were obtained: 

1. percent correct tool actions: 

# of correct tool actions 
total # of tool actions 

2. percent correct nontool actions: 



# of correct nontool actions 
total # of nontool actions 



3. percent correct total actions: 



# of total correct actions (tool + nontool) 

# of total actions (tool + nontool) 

4. action per time ratio: 

total time of meal (seconds) 

total # of errors over the entire meal 

Rater Training 
The rater training protocol used in this study was based on the protocol described 
by Maher (1995). The raters for this study were two graduate students in speech- 
language pathology. The raters were novices in the study of apraxia and unfamiliar with 
the specific research questions in the study. The raters were told that every action the 
subjects produced was important and to make sure that every action was recorded and 
scored. Prior to a scoring session, the raters were given a score sheet and a list of error 
types with definitions and examples. They were asked to record and score a two minute 
portion of a mealtime tape from a previous study. These recordings and scores were 
reviewed with the raters by the examiner. Any discrepancies in scoring were reevaluated 



80 
by watching the pertinent section of the videotape and then discussing the scores. This 
procedure continued until 85% or greater reliability between the raters was achieved over 
16 trials (one trial = one action). At that point, the error types were reviewed by the 
trainer and recording/scoring of test trials began. 

Inter-rater reliability was calculated by selecting four videotapes at random and 
calculating point-to-point reliability for the raters. The raters were not aware of which 
subjects were used for reliability calculations. Two subjects selected at random were 
scored twice by the raters to calculate intra-rater reliability. 

Statistical Analyses 

The statistical analyses were tailored specifically for each of the research 
questions. For question number 1 

Does brain damage in either hemisphere result in production of action errors in 
the natural environment or are action errors specific to left hemisphere brain 
damaged patients? 

the LBD, RBD, and control subjects were compared using an analyses of variance with 

the dependent variable being total number of action errors produced during the eating 

task. Because a negatively skewed distribution was found for the control subjects, a 

nonparametric test, the Kruskal-Wallace, was used. The Wilcoxon Rank Sums Test was 

then used to determine differences between groups. 

For question 2a 

Does presence of deficits in 

1 . production of learned skilled movements, 

2. conceptual knowledge of tool-function relationships, 

3. action planning and organization, and 

4. supervisory attention/working memory 

predict production of action errors in the natural environment? 



81 
Pearson Product Moment Correlations were calculated between the independent 
experimental measures (TOL, FAB, WAB, Trails A, Trails B, Neglect, Tool-Object 
Matching) and total number of action errors produced during the meal. 

For question 2b 

And if so, to what extent does each type of deficit (low level system deficits-- 1 
and 2 above and high level system deficits-3 and 4 above) predict type of error 
(including misuse, mis-selection, external configuration, internal configuration, 
timing, quantity, sequence [omission, addition, sequence], exchange, substitution, 
movement, and body part as tool)? 

A multiple stepwise regression statistic was calculated between the independent measures 
(TOL, FAB, Trails A, Trails B, Tool-Object Matching) and the dependent variables of 
types of errors produced during the meal (misuse, mis-selection, external configuration, 
internal configuration, timing, sequence [omission, addition, sequence], movement, and 
body part as tool. 



CHAPTER THREE 
RESULTS 

The purpose of this study was to examine the nature of movement and action 
errors produced by brain-damaged patients during an activity of daily living-eating a 
meal. Two experimental subject groups and one control subject group participated in this 
study. The first experimental group consisted of twenty left hemisphere brain-damaged 
patients; the second experimental group consisted often right hemisphere brain-damaged 
patients; and the control subject group consisted often neurologically normal control 
subjects. There were no significant differences between the three groups in age F(2, 37) 
= 0.61, p > 0.54 or educational level F(2, 37) = 0.36, p > 0.69. There was also no 
significant different in the time post stroke between the two experimental groups F(l, 28) 
= 2.04, p> 0.16. 

Experimental Results 

Errors of movement and action were theorized to occur at two levels based on the 
low (movement) and high (action) level schema systems proposed by the relationship 
described in Figure 1-4. That is, error types that reflect deficits in the praxis production 
system (Rothi et al, 1991) would make up low level schematic system errors while error 
types that reflect deficits in the planning and organization of action in the executive 
function and control mechanisms (Schwartz & Buxbaum, 1997) would make up high 
level schematic errors. As described in Chapter Two, the evaluation of independent 
variables included tests that were proposed to measure the different deficits that can 



82 



83 



occur within the two levels. The Tower of London (JOL; Shallice, 1982, Krikorian et 
al, 1994) was given to evaluate deficits in the ability to plan and organize actions 
associated with "frontal apraxia", a high level deficit. The Gesture to Command subtest 
of The Florida Apraxia Batterv: Experimental Edition (Rothi et al, 1992) was given to 
evaluate the presence and severity of disorders of learned, skilled movement associated 
with ideomotor apraxia, a low level deficit. A revised version of the Tool-Object 
Matching Test (TOM) described by Ochipa et al, (1989) was given to evaluate deficits in 
tool-function-object knowledge associated with ideational/conceptual apraxia, a low level 
deficit. Additionally, the Trailmaking Test - Parts A & B (Reitan, 1944) was given to 
evaluate deficits in supervisory attention/working memory; The Western Aphasia Batterv 
(WAB; Kertesz, 1981) was given to evaluate presence of aphasia; and a line bisection 
task was used to evaluate presence of neglect. Descriptive statistics for the three groups 
on each of the above tasks are listed in Table 3.1. Overall, the three groups were 
prototypic of their constituents. That is, 70% of the RBD had neglect while only 40% of 
the LBD and none of the controls had neglect. 85% of the LBD had aphasia while none 
of the RBD or controls were aphasic. 65% of the LBD had ideomotor apraxia while 20% 
of the RBD and none of the controls were apraxic. 20% of the LBD and none of the 
RBD or controls had conceptual apraxia. In addition, 80% of LBD and 70% of RBD had 
"frontal apraxia" and were slower on the attention tasks than the controls. 

Neglect and aphasia were ruled out as variables that affected the data by dividing 
all subjects into two groups according to presence/absence of neglect and 
presence/absence of aphasia and comparing the mean number and types of errors 
produced by the two groups. No significant differences between the groups were found. 






84 



Table 3.1 Descriptive Statistics for Each Group on Measures of Independent Variables 
Task Mean SD Max Min 



Tower of London 

LBD 

RBD 

Control 

Total Possible 

Gesture to Command 

LBD 

RBD 

Control 

Total Possible 

Tool-Object Matching 

LBD 

RBD 

Control 

Total Possible 



Trails A 

LBD 86.71 56.98 

RBD 112.2 74.68 

Control 49.2 23.55 

Range for NBD* varies according to age, (Appendix C) 

Trails B 

LBD 208.1 197.45 

RBD 213.5 154.15 

Control 111.3 47.78 

Range for NBD* varies according to age, (Appendix C) 



24.4 


11.21 


24.1 


10.21 


30.8 


3.08 


36 




12.8 


6.03 


20.8 


6.01 


23.0 


3.13 


30 




9.3 


1.94 


10 





10 





10 





34 
33 
35 



25 
27 
28 



10 
10 
10 



3 

5 

26 



3 

10 
17 



3 

10 
10 



232 


26 


231 


39 


95 


21 



925 


67 


561 


100 


199 


66 



Western Aphasia Batterv 










LBD 


69.54 


27.20 


98.2 


10.8 


RBD 


97.92 


1.14 


99.6 


96.1 


Control 


99.02 


0.64 


99.8 


98.2 


Total Possible 


100 








Line Bisection 










LBD 


-1.6 


1.56 


13.3 


-31.04 


RBD 


8.9 


2.87 


25.0 


-2.33 


Control 


2.9 


0.39 


0.67 


-7.00 


Ranee for NBD* 











*NBD= non brain-damaged individuals 



85 

Research Questions 

Research Question #1 

Does brain damage in either hemisphere result in production of action errors in 
the natural environment or are action errors specific to left hemisphere brain 
damaged patients? 

To determine if patients with LBD (left brain damage) and RBD (right brain 

damage) produce action errors in the natural environment, the following null hypothesis 

was tested: 

H : There is no significant difference between the mean number of errors 
produced while eating a meal for the LBD, RBD, and control groups (NBD, non- 
brain damaged). 

Using a Kruskal-Wallis One- Way Analysis of Variance on Ranks (due to the 

skewdness of the control group having produced no errors during the meal), the mean 

number of total errors was compared between the three groups. A significant between 

group difference was found (Table 3.2). 

Table 3.2 Overall Kruskal-Wallis ANOVA for Errors Produced During the Meal 

ANOVA dFTT2l 
Task Chi-Souare H Statistic P-Value _ 

Total Errors 16.091 0.0003* 

Tool Errors 10.496 0.0053* 

Non-Tool Errors 15.479 0.0004* 



* significant at p>0.01 

Because a significant difference was found for total number of errors produced 
during the meal, a follow-up analysis was conducted using the Kruskal-Wallis Multiple 
Comparison Z-Value Test. This test is used to examine group differences with non- 



86 

parametric data. Results of the follow-up analyses, comparing each brain-damaged group 
with the normal controls are listed in Table 3.3. For total number of errors produced 
during the meal, the LBD and RBD groups did not differ from each other. However, 
both groups did differ significantly from the control group. 

Table 3.3 Comparison of LBD and RBD Groups with Normal Controls 



Group 1 vs. Group 2 


Critical Difference 


Actual Difference 


Total Errors 






LBD vs. RBD 


z- value > 1.96 


1.012 


LBD vs. Controls 


z- value > 1.96 


3.997* 


RBD vs. Controls 


z- value > 1.96 


2.585* 


Tool Errors 






LBD vs. RBD 


z- value > 1.96 


2.269* 


LBD vs. Controls 


z-value>1.96 


2.937* 


RBD vs. Controls 


z- value > 1.96 


0.5783 


Non-Tool Errors 






LBD vs. RBD 


z- value > 1.96 


0.568 


LBD vs. Controls 


z-value>1.96 


3.861* 


RBD vs. Controls 


z-value>1.96 


2.851* 



* significant at p>0.01 

In order to determine if the significant difference found for number of total errors 
could be accounted for by differences in number of tool errors and/or nontool errors 
produced by the three groups, additional ANOVAs were calculated for total number of 
tool errors and nontool errors. Significant group differences were found for both tool and 
nontool errors. See Table 3.2 for ANOVA results. To examine between group 
comparisons, follow-up analyses were conducted using the Kruskal-Wallis Multiple 



87 



Comparison Z- Value Test. Results indicated that the LBD group differed significantly 
from both the RBD and control groups in number of tool errors produced but the RBD 
group did not differ from the control group. In addition, both of the LBD and RBD 
groups differed significantly from the control group in number of nontool errors produced 
but the LBD and RBD groups did not differ from each other. (See Table 3.3.) 
Research Question #2a 

2a. Does presence of deficits in 

1 . production of learned skilled movements, 

2. conceptual knowledge of tool-function relationships, 

3. action planning and organization, and 

4. supervisory attention/working memory 

predict production of action errors in the natural environment? 

To determine if there is a relationship between the presence of deficits in 1, 2, 3, 

or 4 above, with production of action errors, the following null hypothesis was tested: 

H : There is no correlation between deficits in 1, 2, 3, or 4 with number of errors 
produced during the eating task across the three subject groups. 

Using a Pearson-Product Moment Correlation Statistic, relationships between 

scores on the Gesture to Command subtest of the Florida Apraxia Battery: Experimental 

Edition (Rothi et ai, 1992) which measures deficit #1 above, the tool-object matching 

test (Ochipa et ai, 1989) which measures deficit #2 above, the Tower of London 

(Shallice, 1982, Krikorian et al, 1994) which measures deficit #3 above, and Trails A 

and Trails B (Reitan, 1944) which measure deficit #4 above, were correlated with total 

number of errors produced during the meal. Results of this analysis revealed that the 

highest correlation was with the TOL and the lowest correlation was with the tool-object 

matching task. All correlations are listed in Table 3.4. 



88 



Table 3.4 Pearson-Product Moment Correlation Report 



Total Errors 



Gesture to Command -0.389 

Tool-Object Match -0.083 

Tower of London -0.550 

Trails A 0.247 

Trails B 0.244 



In addition to the correlation statistic, all subjects were divided into two groups 
according to the normal versus abnormal cut-off score for each of the independent 
variables. Two sample t-tests were then calculated for the mean number of overall errors 
(total, tool, and non-tool) as well as for the mean number of specific error types (misuse, 
misselection, movement, INT, sequence, timing, and quantity) produced by the 
normal/abnormal groups. Parametric or non-parametric t-tests were chosen based on the 
normalcy and the variance of the data within each error type on these various tests. 
These divisions and analyses were completed in order to obtain a better understanding of 
the influence of the grouping variables (deficits in #1, 2, 3, and 4 from question 2a) on 
error types in these various tests. 

On the gesture to command task, all subjects were divided into two groups-those 
subjects scoring 14 or below, indicating presence of ideomotor apraxia (IMA), were in 
group 1 while those subjects scoring 15 or above indicating normal praxis skills (i.e. non- 
IMA) were in group 2 (Rothi et al, 1992). Group 1 consisted of 15 subjects while group 
2 consisted of 25 subjects. The two groups were then compared in each of the overall 
and specific error types listed previously. Results indicated that there were significant 



89 

differences between the two groups at the p<0.01 level for total number of errors as well 
as for number of tool, misuse, movement, timing, and quantity errors produced during the 
meal. In contrast, no significant differences were found for number of non-tool errors as 
well as for number of misselection, INT, and sequence errors produced during the meal. 
See Tables 3.5 and 3.6. 



Table 3.5 Average Number of Errors Produced by All Subjects When Divided into 
Two Groups According to Cut-Off Score for Each Test. 



Test 



Cut-Off 
Score 



n Average Number of Errors 

Total Tool NonTool 



Ideomotor 
Apraxia 1 


15-30 
<15 




25 
15 


4.32* 
17.87 


Conceptual 
Apraxia 2 


10 
<10 




36 
4 


8.97* 
14.33 


"Frontal 
Apraxia" 3 


33-36 

<33 




12 
28 


1.25* 
12.63 


Attention 4 


>25 th 
<25 th 


per. 
per. 


18 
18 


1.94* 
10.44 


Divided 
Attention 5 


>25 th 
<25 th 


per. 
per. 


19 
16 


3.26* 
9.94 



1.08* 
9.87 

4.00* 
9.33 

0.17* 
5.88 

1.50 

4.22 

0.11* 
6.31 



3.24 
7.93 

4.94* 
5.00 

1.10* 
6.71 

0.45* 
6.16 

3.16* 

3.56 



'Rothi etai, 1992 

2 0chipaefa/.,1992 

3 Krikorianera/.,1994 

45 Spreem and Strauss, 1991 

n = number of subjects in group 

per. = percentile 

* - significant at the pO.Ol level 



90 



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91 

On the tool-object matching task, all subjects were divided into two groups 
according to the following criteria. Those subjects scoring 9 or below, indicating 
presence of conceptual apraxia were in group 1 while those subjects scoring 10, 
indicating normal praxis skills, were in group 2 (Ochipa et al, 1992). Group 1 consisted 
of 4 subjects while group 2 consisted of 36 subjects. The two groups were then compared 
in each of the overall and specific error types listed previously. Results indicated that 
there were significant differences between the two groups at the p<0.01 level for total 
number of errors as well as for number of tool and non-tool errors produced during the 
meal. In contrast, no significant differences were found for number of misuse, 
misselection, movement, INT, sequence, timing, or quantity errors produced during the 
meal. See Tables 3.5 and 3.6. 

On the TOL task, all subjects were divided into two groups-those subjects 
scoring 32 or below, indicating presence of frontal apraxia were in group 1 while those 
subjects scoring 33 or above, indicating normal praxis skills, were in group 2 (Krikorian 
et al, 1994). Group 1 consisted of 28 subjects while group 2 consisted of 12 subjects. 
The two groups were then compared in each of the overall and specific error types listed 
previously. Results indicated that there were significant differences between the two 
groups at the p<0.01 level for total number of errors as well as for number of tool, non- 
tool, sequence, and quantity errors produced during the meal. In contrast, no significant 
differences were found for number of misuse, misselection, movement, INT, and timing, 
errors produced during the meal. See Tables 3.5 and 3.6. 

Fourth, all subjects were divided into two groups according to Trails A score. 
The criterion for this division was based on Table 8.12 (page 326) in A Compendium of 



92 



Neuropsychological Tests (Spreem & Strauss, 1991) which is a summary of normative 
data for completion of the Trails A task. Subjects were placed in group 1, indicating 
presence of poor attentional skills, if their time to complete Trails A was below the 25 
percentile for their age. Subjects were placed in group 2, indicating normal attentional 
skills, if their time to complete Trails A was above the 25 th percentile for their age group. 
Group 1 consisted of 18 subjects and group 2 also consisted of 18 subjects (four subject 
were unable to complete the task). The two groups were then compared in each of the 
overall and specific error types listed previously. Results indicated that there were 
significant differences between the two groups at the p<0.01 level for total number of 
errors as well as for number of non-tool, movement, timing and quantity errors produced 
during the meal. In contrast, no significant differences were found for number of tool, 
misuse, movement, INT, and sequence errors produced during the meal. See Tables 3.5 

and 3.6. 

Finally, all subjects were divided into two groups according to Trails B score. 
The criterion for this division was also based on Table 8.12 (page 326) in A Compendium 
of Neuropsychological Tests (Spreem & Strauss, 1991) which is a summary of normative 
data for completion of the Trails B task. Subjects were placed in group 1, indicating 
presence of poor divided attentional skills, if their time to complete Trails B was below 
the 25 th percentile for their age. Subjects were placed in group 2, indicating normal 
divided attentional skills, if their time to complete Trails B was above the 25 percentile 
for their age group. Group 1 consisted of 16 subjects and group 2 consisted of 19 
subjects (five subjects were unable to complete the task). The two groups were then 
compared in each of the overall and specific error types listed previously. Results 



93 

indicated that there were significant differences between the two groups at the p<0.01 

level for total number of errors as well as for number of tool, non-tool, misuse, 

movement, and quantity errors produced during the meal. In contrast, no significant 

differences were found for number of misselection, INT, sequence, and timing errors 

produced during the meal. See Tables 3.5 and 3.6. 

Research Question 2b 

2b. And if so, to what extent does each type of deficit (low level schema deficits- 
-1 and 2 from question 2a above and high level schema deficits--3 and 4 from 
question 2a above) predict type of error (including misuse, mis-selection, external 
configuration, internal configuration, timing, quantity, sequence, exchange, 
substitution, movement, and body part as tool)? 

To determine if there is a relationship between the types of deficits (lower or 
higher level schema) and types of errors produced during the meal, a multiple stepwise 
regression statistic was calculated between the independent variables, FAB, tool-object 
match (TOM), TOL, Trails A, and Trails B, and the types of errors observed during the 
meal (tool, non-tool, and total errors as well as the individual types: misuse, misselection, 
internal configuration, movement, sequence, timing, and quantity). The results indicated 
that 0.22% of the variance for total errors can be explained through iteration 4 which 
included the FAB, TOL, Trails A, and TOM, respectively. The results of the multiple 
stepwise regression for total errors are displayed in Table 3.7. 



94 



Table 3.7 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Total Errors Produced During the Meal 



Model Size R z Model 



1 0.11 Trails A 

2 0.16 FAB + TOL 

3 0.19 FAB + TOL + Trails A 

4 0.23 FAB + TOL + Trails A + TOM 



The results indicated that 0.37% of the variance for tool errors can be explained 
through iteration 4 which included the FAB, TOL, Trails A, and Trails B, respectively. 
The results of the multiple stepwise regression for tool errors are displayed in Table 3.8. 



Table 3.8 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Tool Errors Produced During the Meal 



Model Size R 2 Model 



1 


0.24 


Trails A 


2 


0.26 


FAB + Trails A 


3 


0.32 


FAB + TOL + Trails A 


4 


0.37 


FAB + TOL + Trails A + Trails B 


5 


0.37 


FAB + TOL + Trails A + Trails B + TOM 



The results indicated that 0.06% of the variance for non-tool errors can be 
explained through iteration 2 which included the TOL, and TOM, respectively. The 
results of the multiple stepwise regression for non-tool errors are displayed in Table 3.9. 



95 



Table 3.9 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Non-Tool Errors Produced During the Meal 



Model Size 


R 1 


1 


0.02 


2 


0.06 


3 


0.06 


4 


0.06 


5 


0.06 



Model 



TOL 

TOL + TOM 

TOL + Trails B + TOM 

TOL + Trails A + Trails B + TOM 

FAB + TOL + Trails A + Trails B + TOM 



The results indicated that 0.25% of the variance for misuse errors can be 
explained through iteration 3 which included the FAB, TOL, and Trails A, respectively. 
The results of the multiple stepwise regression for misuse errors are displayed in Table 
3.10. 



Table 3.10 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Misuse Errors Produced During the Meal 



Model Size 


R z 


1 


0.19 


2 


0.22 


3 


0.25 


4 


0.26 


5 


0.26 



Model 



Trails A 

FAB + Trails A 

FAB + TOL + Trails A 

FAB + TOL + TRAILS A + TRAILS B 

FAB + TOL + TRAILS A + TRAILS B + TOM 



The results indicated that 0.09% of the variance for misselection errors can be 
explained through iteration 4 which included the FAB, TOL, Trails A, and TOM, 
respectively. The results of the multiple stepwise regression for misselection errors are 
displayed in Table 3.11. 



96 



Table 3.11 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Misselection Errors Produced During the Meal 



2 



Model Size R z Model 



1 


0.02 


2 


0.06 


3 


0.08 


4 


0.09 


5 


0.09 



TOM 

TOL + TOM 

FAB + TOL + TOM 

FAB + TOL + Trails B + TOM 

FAB + TOL + Trails A + Trails B + TOM 



The results indicated that 0.535% of the variance for movement errors can be 
explained through iteration 4 which included the FAB, TOL, Trails A, and Trails B, 
respectively. The results of the multiple stepwise regression for movement errors are 
displayed in Table 3.12. 



Table 3.12 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Movement Errors Produced During the Meal 



2 



Model Size R z Model 



1 


0.36 


2 


0.39 


3 


0.45 


4 


0.53 


5 


0.53 



Trails A 

TOL + Trails A 

FAB + TOL + Trails A 

FAB + TOL + Trails A + Trails B 

FAB + TOL + Trails A + Trails B + TOM 



The results indicated that 0.19% of the variance for INT errors can be explained 
through iteration 5 which included the FAB, TOL, Trails A, Trails B, and TOM, 
respectively. The results of the multiple stepwise regression for INT errors are displayed 
in Table 3.13. 



97 



Table 3.13 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and INT Errors Produced During the Meal 



Model Size R Model 



1 0.07 Trails A 

2 0.10 Trails A + TOM 

3 0.13 TOL + Trails A + TOM 

4 0.17 FAB + TOL + Trails A + Trails B 

5 0.19 FAB + TOL + Trails A + Trails B + TOM 



The results indicated that 0.05% of the variance for sequence errors can be 
explained through iteration 4 which included the FAB, TOL, Trails A, and TOM, 
respectively. The results of the multiple stepwise regression for sequence errors are 
displayed in Table 3.14. 

Table 3.14 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Sequence Errors Produced During the Meal 



Model Size R Model 



1 0.02 Trails A 

2 0.03 Trails A + TOM 

3 0.04 TOL + Trails A + TOM 

4 0.05 FAB + TOL + Trails A + TOM 

5 0.05 FAB + TOL + Trails A + Trials B + TOM 



The results indicated that 0.08% of the variance for timing errors can be explained 
through iteration 4 which included the TOL, Trails A, Trails B, and TOM, respectively. 
The results of the multiple stepwise regression for timing errors are displayed in Table 
3.15. 






98 



Table 3.15 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Timing Errors Produced During the Meal 



Model Size 



R z 



Model 



1 


0.02 


TOL 


2 


0.05 


TOL + TOM 


3 


0.06 


TOL + Trails A + TOM 


4 


0.08 


TOL + Trails A + Trails B + TOM 


5 


0.08 


FAB + TOL + Trails A + Trials B + TOM 



The results indicated that 0.10% of the variance for quantity errors can be 
explained through iteration 2 which included the TOL and TOM, respectively. The 
results of the multiple stepwise regression for quantity errors are displayed in Table 3.16. 



Table 3.16 Results of Multiple Stepwise Regression Analysis Between Independent 
Variables and Quantity Errors Produced During the Meal 



Model Size 



R 2 



Model 



1 


0.03 


2 


0.10 


3 


0.10 


4 


0.10 


5 


0.10 



TOL 

TOL + TOM 

TOL + Trails A + TOM 

TOL + Trails A + Trails B + TOM 

FAB + TOL + Trails A + Trails B + TOM 



Summary of findings 

Regarding research question #1, it was found that: 

• Patients with either LBD or RBD produce action errors during an eating 
task. 



99 

• People without brain damage do not tend to produce action errors during 
an eating task. 

• LBD patients produce more tool action errors during an eating task than 
RBD patients who do not produce more of these errors than normal 
subjects. 

• LBD and RBD patients produce equal amounts of non-tool errors during 
an eating task, both of whom produce more of these errors than normal 
subjects. 

Regarding research question #2a, it was found that 

• Presence of deficits in the production of learned, skilled movements to 
command, does predict presence of action errors in the natural 
environment. 

• Presence of deficits in the conceptual knowledge of tool-function 
relationships, does predict presence of action errors in the natural 
environment. 

• Presence of deficits in the action planning and organization, does predict 
presence of action errors in the natural environment. 

• Presence of deficits in the supervisory attention/working memory, do 
predict presence of action errors in the natural environment. 

Additionally, 

• The measure of deficits in action planning and organization was the 
strongest predictor while the measure of deficits in conceptual knowledge 






100 



of tool-function relationships was the weakest predictor of total number of 
errors produced by the brain damaged patients during the eating task. 

• Presence of deficits in production of learned, skilled movements appeared 
to influence production of tool but not non-tool errors during the eating 
task. 

• Presence of deficits in supervisory attention/working memory appeared to 
influence production of non-tool but not tool errors. 

• Presence of deficits in conceptual knowledge of tool-function 
relationships, and action planning and organization appeared to influence 
production of both tool and non-tool errors. 

Regarding research question #2b, it was found that 

• Neither low nor high level schema deficits independently predicted type of 
errors produced during the eating task, however, low and high level 
schema deficits when combined, predicted each error type produced 
during the eating task. 

• However, the degree of their respective contributions varied according to 
error type produced during the eating task with movement errors receiving 
the strongest influence from both low and high level schema deficits 
followed by misuse, INT, quantity, timing, and sequence, respectively. 



CHAPTER FOUR 
DISCUSSION 

Previous researchers have described errors of action produced during 

activities of daily living by patients with brain damage (Mayer et al, 1990; Schwartz 

etal, 1991, 1993, 1995; Schwartz & Buxbaum, 1997; Ochipa <?/ a/. , 1989; Foundas et 

al, 1995). However, each research team has examined the planning, organization, 

and production of these action errors through different theoretical models with 

different inherent assumptions and predictions. They have used different research 

hypotheses arid evaluation criteria. Moreover, they have included subjects with 

heterogeneous etiologies of brain damage (Mayer et al, 1990; Schwartz et al, 1991, 

1993, 1995; Schwartz & Buxbaum, 1997; Sirigu <?/ a/. , 1995a, 1995b, 1997; Ochipae/ 

al, 1989; Foundas et al, 1995). The purpose of the current study was to examine the 

nature of action errors produced by brain-damaged patients during an activity of daily 

living— eating a meal— using a theoretical model which describes a proposed 

relationship between apraxia and pragmatic action. This model serves as a 

framework for the examination of the nature of action as well as movement errors and 

allows for comparison with models proposed by the previous researchers. Two 

experimental subject groups and one control subject group participated in this study. 

The first experimental group consisted of twenty left hemisphere brain-damaged 

patients (LBD); the second experimental group consisted often right hemisphere 

brain-damaged patients (RBD); and the control subject group consisted often 



101 



102 



neurologically-normal control subjects. The groups were compared on experimental 
tasks designed to measure the deficits associated with impairment in action planning 
and organization (i.e., frontal apraxia, a high level schema deficit), deficits in the 
production of learned, skilled movements (i.e., ideomotor apraxia, a low level schema 
deficit), deficits in conceptual knowledge of tool-object-function relationships (i.e., 
conceptual apraxia, a low and/or high level schema deficit), and deficits in 
supervisory attention/ working memory (high level schema deficit). Each subject was 
also videotaped while engaged in an activity of daily living-eating a meal-and the 
videotapes were subsequently scored for the presence of and type of movement and 
action errors. Statistical analyses then compared the groups for differences in the 
number and type of errors produced. Results indicated that the LBD, RBD, and 
control groups did differ in both the number and type of errors produced during the 
eating task which suggests that action errors can occur following unilateral damage to 
either hemisphere. Additionally, further analyses revealed that the number and type 
of errors produced differed according to the presence or the absence of higher and/or 
lower level schema deficits. Furthermore, this finding suggests that a stronger 
relationship appears between disorders of planning and organization (higher level 
schemas) and action errors during activities of daily living than disorders of learned, 
skilled movement (lower level schemas) and action errors during activities of daily 
living. However, both levels of deficits do contribute to production of errors in the 
natural environment. This chapter will discuss the results of the current study in 
respect to: 1) the research questions posed in Chapter One and results of previous 



103 



research, 2) clinical implications, 3) methodological issues and limitations of the 
study, and 4) implications for future research. 

Research Questions 
The primary question of interest for this study was: Does brain damage in 
either hemisphere result in production of action errors in the natural environment or 
are action errors specific to left hemisphere brain damaged patients? The major 
finding of this study was that brain damage in either hemisphere does result in 
production of action errors in the natural environment. Results indicated that both 
the LBD and the RBD groups produced significantly more errors overall than the 
control group. When the types of errors were broken down into tool errors and non- 
tool errors, the LBD and RBD groups differed from each other as well as with the 
controls. The LBD group produced significantly more tool errors than the RBD and 
the control group while the RBD group did not differ significantly from the control 
group. This difference was predicted in Chapter One where it was hypothesized that 
tool errors may be related to the presence of ideomotor apraxia, a low level schema 
deficit, in patients with damage to the dominant hemisphere. That is, previous 
research has shown that the visuokinesthetic engrams for learned skilled movement, 
which are damaged in ideomotor apraxia, are lateralized to the dominant (left) 
hemisphere. It would therefore be expected that the presence of ideomotor apraxia 
may affect production of tool errors and would be observed in the LBD group. 
Overall, thirteen of the twenty LBD subjects presented with ideomotor apraxia, while 
only two of the ten RBD subjects and no control subjects had ideomotor apraxia as 
defined by the Rothi et al. (1992) criteria. 



104 



Additionally, the LBD and RBD groups did not differ from each other, but 
both groups did differ significantly from the control group, in the number of non-tool 
errors produced during the meal. This finding was also predicted in Chapter One 
where it was hypothesized that non-tool errors may be more closely related to deficits 
in executive function and/or supervisory attention/working memory (high level 
schema deficits) which follow damage to either the dominant or non-dominant 
hemisphere. That is, both executive functions and supervisory attention/working 
memory have bilateral representation in the brain and can be impaired following 
damage to either hemisphere. In fact, all twenty LBD subjects and all ten RBD 
subjects demonstrated deficits in executive function (according to Krikorian et al. 
criteria 1994) and/or supervisory attention/working memory (according to Spreem & 
Strauss, 1991, criteria). 

Furthermore, when the total number of errors produced was compared, the 
LBD subjects produced significantly more errors than the RBD subjects. This was 
also predicted in Chapter One where it was hypothesized that the LBD subjects were 
more likely to demonstrate both low level and high level schema deficits while the 
RBD subjects were more likely to demonstrate high level deficits only. As a result 
of this difference, the LBD subjects would have had more opportunities to produce 
errors secondary to deficits in both high and low level schemas. 

The second research question was presented in two parts: Does presence of 
(a) deficits in production of learned skilled movements, (b) deficits in conceptual 
knowledge of tool-function relationships, (c) deficits in action planning and 
organization, and/or (d) deficits in supervisory attention/working memory predict 



105 



production of action errors in the natural environment? And if so, to what extent does 
each type of deficit (low level system deficits [a and b above] and high level system 
deficits [c and d above]) predict type of error (including misuse, mis-selection, 
external configuration, internal configuration, timing, quantity, sequence [omission, 
addition, sequence], exchange, substitution, movement, and body part as tool)? To 
answer the first question, a correlation statistic was calculated between the 
independent variables and the types of errors produced during the meal. Results 
indicated that overall, the measure of executive function had the highest correlation 
with all error types, tool, non-tool, and total errors. Also, the measure of ideomotor 
apraxia had the second highest correlation across all error types. These results also 
appear to support the hypothesis that high level schema deficits may "oversee" or 
dominate the entire action sequence and therefore may influence errors of each type 
within that action sequence when damaged. The fact that a measure of a low level 
schema deficit (ideomotor apraxia) had the next highest correlation across error types 
may indicate that low level schemas are equally important in the success of 
completing pragmatic actions as high level schemas. It was proposed in the described 
relationship between pragmatic action and apraxia in Chapter One that the final 
common pathway for pragmatic action was through the praxicon and movement 
formulae associated with low level schemas. Due to the close relationship between 
executive functions which govern pragmatic action overall, and the praxis system 
which governs the individual movement patterns which make up the pragmatic action 
components, it is logical that both would positively correlate with production of 
errors within natural contexts. It therefore also appears, that conceptual knowledge 



106 



about the relationship between tools and objects as well as supervisory 
attention/working memory may not play as important of a role in contributing to 
production of action errors because their correlations with the error types was not as 
high as either executive functions or ideomotor apraxia. This finding appears to 
contradict Ochipa et al. (1989), Schwartz et al. (1995), and Reason (1990). Ochipa et 
al. (1989) reported that their subject produced errors secondary to a deficit in 
conceptual knowledge about tool-object relationships while both Schwartz et al. 
(1995), and Reason (1990) discussed the importance of supervisory attention/working 
memory in "preventing" and "catching" action errors before they occur. However, 
the current study does not negate the importance of either conceptual knowledge of 
tool-object relationships or supervisory attention/working memory in producing 
pragmatic action. The significance of both was discussed in the proposed relationship 
between pragmatic action and apraxia in Chapter One. However, the current study 
does examine the roles of these components in regard to the production of action 
errors in brain-damaged patients. Within this context, it appears that executive 
function and ideomotor apraxia appear to correlate more highly than either conceptual 
knowledge of tool-object relationships or supervisory attention/working memory in 
the production of action errors during an activity of daily living. 

To answer the latter part of the second question, the subjects were divided into 
two groups according to the presence or absence of each independent variable and t- 
tests were calculated between the two groups for each error type observed. When 
subjects were divided according to presence or absence of ideomotor apraxia, a low 
level schema deficit, it was predicted that error types associated with low level 



107 



schema deficits would predominate. However, the subjects with ideomotor apraxia 
produced errors in each category, not just those associated with low level schemas. 
Additionally, when the subjects were divided according to presence or absence of 
executive function disorders, conceptual knowledge of tool-object relationships, and 
supervisory attention/working memory, all high level schema deficits, the error types 
produced also were categorized into each category, not just those associated with high 
level schemas. Therefore, in order to better understand the relationship between each 
component and the error types, the relative pattern of errors must be compared and 
not just whether or not the error was produced. When the pattern of errors is 
compared, it appears that both presence of executive function disorders and 
ideomotor apraxia result in a high number of misuse and quantity errors. Both misuse 
and quantity errors are the only error types which can be explained by both low level 
and high level schema deficits. For misuse errors resulting from a low level schema 
deficit, the error would result from choosing the wrong action for the tool (or vice 
versa) while a high level schema deficit would result from using the tool from a 
previous action for the next action without considering that it is the wrong action. For 
quantity errors resulting from low-level schema deficits, the error would result from a 
deficit in the acknowledgement of the mechanical advantage that tools provide (e.g., a 
spoon can only hold so much mashed potatoes without compromising the efficiency 
of the action) while quantity errors resulting from high level schemas result from the 
failure of the attentional system to mediate an inappropriate action. 

When the pattern of errors is compared following the division of the subjects 
according to presence or absence of deficits in supervisory attention/working 



108 



memory, not only do misuse and quantity errors predominate, but also timing errors. 
This appears to indicate that misuse and quantity errors are the most prevalent errors 
following brain damage. It also suggests that attentional deficits contribute to timing 
errors. This relationship is also logical in that if one is not paying attention to the 
task, one may lose track of what action is supposed to be produced next and may 
therefore take extra time in deciding what action plan to initiate next in order to 
complete the task. 

When the pattern of errors is compared following the division of the subjects 
according to presence or absence of deficits in the conceptual knowledge of tool- 
object relationships, the predominate error types were not misuse and quantity but 
movement and INT. This finding appears to contradict the proposal that deficits in 
the conceptual knowledge of tool-object relationships is a high level schema deficit 
because both movement and INT errors are specifically observed and produced by 
patients with ideomotor apraxia, a low level schema deficit. However, only four of 
the thirty brain damaged patients presented with deficits in the conceptual knowledge 
of tool-object relationships and these same four subjects also had severe ideomotor 
apraxia. It may be possible that the error patterns are a reflection of the severe 
ideomotor apraxia rather than a specific deficit in the conceptual knowledge of tool- 
object relationships. 

Results of the above error pattern analyses support the proposals described by 
Schwartz et al. (1992, 1995) that errors produced by brain-damaged patients can 
result from an impairment in either the top-down or bottom-up level of processing. In 
this study, top-down processing would reflect deficits in high level schemas 



109 



influencing deficits in low-level schemas while bottom-up processing would reflect 
deficits in low level schemas that appear to be produced independently of high level 
"supervision" during the task. Subjects in the current study produced error types 
following both of these scenarios. Schwartz et al. (1992, 1995) also proposed that 
actions are not whole programs, but are organized into hierarchies that are activated 
in succession by the executive function system in order to complete the task. If this is 
true, then different parts of an action plan may be differentially affected by errors 
depending on the high versus low level of deficits. This was also observed in the 
errors produced by subjects in the current study. The overall task of eating a meal 
was completed but the subjects produced errors throughout and the errors were not 
produced consistently on the same action. 

These results also appear to add additional information to the results of the 
Foundas et al. (1995) study. Foundas and colleagues reported that the errors of action 
observed in their subjects resulted from presence of ideomotor apraxia. However, 
Foundas et al. (1995) did not test for deficits in high level schemas and the subjects 
from both the Foundas et al. (1995) and the current study were patients with 
unilateral damage to either hemisphere following a stroke. It would appear that the 
deficits in high level schemas demonstrated by the stroke patients in the current study 
may also have been present in the subjects from the Foundas et al. (1995) study. 
Therefore, the errors produced by the subjects in the Foundas et al. (1995) study may 
also have been influenced by deficits in high level schemas. 

In order to determine the degree of influence from each type of deficit, high 
level schema and low level schema, an all-possible regression statistic was calculated 



110 






between the independent variables and the specific error types. Results of these 
analyses revealed that no one independent variable can be distinguished from any 
other independent variable in their relative influence to production of action errors. 
That is, each error type appears to be influenced by both high and low level schema 
deficits. This finding also supports proposals made by Schwartz and Buxbaum 
(1997) in their discussion of the Unified Hypothesis. Schwartz and Buxbaum (1997) 
argued that it is the combination of deficits that results in action errors in natural 
contexts. That is, deficits in executive function may not result in action errors unless 
a deficit in the automaticity of the action schemas is also present. This may be 
observed in the present study by defining automaticity of action schemas as a low 
level schema deficit in the praxicon, which holds the programs for learned, skilled 
movements. By using this definition, only a combination of high level schema 
deficits and low level schema deficits should result in production of action errors. 
When this criteria is applied to the subjects in the current study, only one subject did 
not evince deficits in both high and low level schemas and this subject did not 
produce any action errors during the meal. Although this appears to support Schwartz 
and Buxbaum's (1997) proposal, there were an additional eleven subjects who 
presented with high level schema deficits only who did produced action errors during 
the meal. These eleven subjects should not have produced errors if Schwartz and 
Buxbaum's (1997) proposals were valid. It is also interesting to note that none of the 
subjects in the current study who demonstrated low level schema deficits had spared 
high level schemas. This would appear to support the bilateral nature of the high 



Ill 



level schemas as well as the lateralization of low level schemas discussed in the 

previous section. 

Methodological Issues and Limitations of the Study 
The results of this research must be interpreted within the context of the 
limitations of the study. One possible area of concern involves subject selection. All 
experimental subjects did have CT/MRI documentation of single, unilateral strokes 
but the time post onset varied from one month to 261 months (21 .9 years) post stroke. 
It is possible that the subjects who had survived their stroke for a longer period of 
time had developed coping skills and strategies for actions. However, when 
evaluating the data, even the subjects with the longest post-onset time produced errors 
of action. The presence of dysphagia was an exclusionary criteria because the 
subjects needed to eat a meal of regular consistency in order to give them opportunity 
to use all three utensils. It is possible that stroke patients with swallowing disorders 
may have greater deficits in action errors than stroke patients without swallowing 

disorders. 

It may also be a concern that the procedures or evaluations chosen to measure 
the independent variables (TOL for executive function disorders, FAB for ideomotor 
apraxia, tool-object matching task for conceptual disorders of tool-object function 
knowledge, and Trails A and Trails B for supervisory attention/working memory 
disorders) may not be the most sensitive or valid. These measures were chosen due to 
their ease in administration. The subjects were able to comprehend the directions and 
perform the tasks accordingly. If more complex or longer measures had been chosen, 



112 



it would have been very possible that many of the aphasic subjects would not have 
been able to perform the task and important data would have been lost. 

One other area of concern is that all subjects ate different meals. Although all 
meals consisted of the same categories of food-a main course, at least one side dish, 
a dessert, and a beverage«the types of food within each category varied greatly. One 
subject may have steak and potatoes while another had spaghetti and garlic bread and 
another had chicken fajitas and a side salad. Although each type of meal provided 
opportunity to use all three untensils (knife, fork, and spoon), it is possible that a 
subject may have received a meal that was easier or harder for him/her to eat than 
they would have normally chosen. However, controlling the type of food received 
by every subject was beyond the scope of this study. It is suggested that every 
opportunity be made in future studies to limit the variability of the food served. 

A final consideration is that the subjects did not produce all of the error types 
proposed in Chapter One. This does not necessarily mean that the error types that 
were not demonstrated by the subjects do not exist. In fact, all error types discussed 
have been reported in other studies (Foundas et ai, 1995; Ochipa et ai, 1989; Mayer 
et ai, 1990; Schwartz et ai, 1991, 1993, 1995; and Schwartz & Buxbaum, 1997). It 
is possible that the error types that were not produced may be less frequently 
produced in general and that a larger number of subjects may have been necessary to 
provide ample opportunity for the less frequent error types to be produced. 

A final concern pertains to the raters who scored the videotapes of the meal 
and documented the error types. The raters were not aware of the hypotheses of the 
study nor were they familiar with the Cognitive Neuropsychological Model of Limb 



113 



Praxis and Apraxia or the Unified Hypothesis. This was done to limit the effects of 
rater bias on judging the presence of action and movement errors and to strengthen 
the internal validity of the study. Only one previous study (Maher, 1995) has 
employed the same degree of control over this issue. As Maher (1995) reported, one 
possible limitation of this control is that the raters are dependent upon the trainer to 
accurately describe correct versus incorrect actions and movements. As a result, any 
biases the trainer may have could have influenced the raters. To control for this in the 
current study, the raters were given written descriptions of each error type and 
underwent a pre-scoring practice session of subjects not included in the study before 
undertaking scoring of actual videotapes from the subjects in this study. Therefore, 
the raters took their responsibilities seriously and were stringent in their decisions of 
whether an action or movement contained an error and then what type of error was 
demonstrated. Since the videotapes of all subjects were scored under these strict 
guidelines, it does not appear that rater bias affected the results. 

Implications for Future Research 
The results of this study are interesting and lead to further questions and 
possible research endeavors within the areas of limb praxis, pragmatic action, 
conceptual apraxia, and supervisory attention/working memory. Although the 
subjects in the current study had documented unilateral lesions, only laterality of 
lesion to the dominant (left) or non-dominant (right) hemisphere was taken into 
consideration. It is possible that mapping the size and location of the lesion within 
the hemisphere may lead to even greater conclusions regarding the relationship 
between brain-behavior relationships. This is especially true when the proposals for 



114 

location of the visuokinesthetic engrams for learned skilled movement associated 
with ideomotor apraxia have been determined to be in the inferior parietal lobule of 
the dominant hemisphere and that executive function disorders result from frontal 
lesion of either hemisphere. Therefore questions arise in that do all patients with 
frontal lobe lesions demonstrate high level schema deficits in the natural 
environment? Do patients with posterior lesions, especially left parietal lesions 
demonstrate low-level schema deficits in the natural environment? 

Additionally, studies are indicated that use similar evaluation criteria of the 
independent variables in subjects with brain damage from different etiologies such as 
traumatic brain injury (TBI) and dementia. Although Schwartz et al. (1992, 1995) 
and Ochipa (1989) did evaluate patients with these different etiologies, both high and 
low level schema deficits were not systematically evaluated. Therefore, it is not 
known to what extent the role of high and low level schema deficits contributed to the 
production of action errors in their subjects. 

Future studies should also take into consideration the possibility of observing 
brain-injured patients in their final type of residence. All of the subjects in the current 
study were evaluated either in a research laboratory, their room at a rehabilitation 
facility, or in the speech and hearing clinic associated with a university. This was 
done in order to control the categories of food the subjects received for their meals. 
However, it would be more "natural" to observe the subjects either within their own 
home or "final destination" {e.g., an assisted living facility, adult family home, or 
skilled nursing facility) and eating food that they have chosen or prepared themselves. 
In addition, attempts should be made to observe or videotape the subjects without the 



115 

subjects being aware of the observation. All of the subjects in the current study were 
aware that they were being videotaped but were unaware of the nature of the study 
(i.e., that their actions and errors were going to be examined). It is possible that just 
knowing that they were being videotaped led to increased consciousness of their 
actions. 

Another lead for future studies would involve locating and evaluating subjects 
with only one deficit. For example, this might involve subjects with ideomotor 
apraxia who do not have executive function or supervisory attention/working memory 
disorders and so forth. By evaluating these "purer" subjects, a better understanding 
of the role of each type of disorder within the high and low schema frameworks may 
be delineated. Unfortunately, these subjects are rare and it is possible that the deficits 
described in the current study are more indicative of the "average" brain-injured 
patient. 

Other issues that should be addressed in future studies include the relationship 
between neglect and the origination of the movements in space during activities of 
daily living. Do patients with neglect produce actions originating in the neglected 
hemispace during activities of daily living? Do their actions move into or end in the 
neglected hemispace? Also, does overall time to eat a meal or organization of the 
meal differ across left and right hemisphere damaged patients? Foundas et al. (1995) 
reported that time to eat was longer for the left hemisphere damaged patients than for 
the controls and that the left hemisphere damaged patients did not respect the 
boundaries of the different meal stages. It is not known whether patients with right 
hemisphere damage would demonstrate these same deficits. 



116 



In all, research into the nature of action and movement errors in activities of 
daily living, pragmatic action, and real-life effects of ideomotor apraxia appear to be 
exciting, clinically relevant, and productive endeavors. 

Clinical Implications 

The degree to which action errors were produced by patients in the current 
study is interesting in that none of the caregivers (i.e., nurses or family members) 
reported that the patient had been producing errors. Additionally, there is a scarcity 
of reports in the literature that describe errors of action produced in natural contexts 
by a group of brain damaged patients. Since twenty-four of the thirty brain damaged 
patients in the current study produced errors of action following a unilateral stroke, it 
is very probable that these errors of action go undetected within the controlled 
environment of an acute care hospital, rehabilitation center, or nursing home. It is 
also feasible that any person who suffers a brain injury is susceptible to produce 
action errors secondary to high level schema deficits that follow damage to either 
hemisphere. If this is true, then there are significant implications for caregivers and 
rehabilitation professionals for these brain-injured people. The caregivers should be 
aware of the potential danger in which the brain-injured patient is placed when in an 
unsupervised or uncontrolled environment. One example described by Ochipa (1989) 
was of a patient who was preparing to brush teeth in the bathroom but picked up the 
razor instead of the toothbrush. The inherent danger in that scenario is obvious to 
even those not familiar with deficits seen following brain injury. However, in order 
to control potentially dangerous situations, the caregiver must be made aware of the 
possibility that the brain-injured patient can and will produce these action errors. 



117 

Unfortunately, this is an area about which not many rehabilitation professionals are 
aware and subsequently may not adequately inform the caregiver (Ochipa, 1989; 
Foundas et al, 1995). Moreover, once caregivers are made aware of the possibility of 
putting the brain-injured patient in dangerous situations, the management of the 
problem is relatively easy to administer. The management involves educating the 
caregiver and any other significant individual who will be working with that patient 
as to ways of controlling the environment so as not to put the individual at risk. 
These suggestions for management were described by Ochipa (1989) and are 
reiterated here: 

1 . Limit access to dangerous tools (knives, razors, etc.). 

2. Limit the available selection of tools for a particular task (e.g. a razor 
should not be within reach when the person is brushing his/her teeth). 

3. Tools should only be used in tasks that are familiar to the patient. Tool 
use in novel or new contexts should be avoided. 

4. Tasks involving the use of multiple tools should be avoided. 

5. Any task that requires the use of potentially dangerous tools should be 
strictly supervised. 

Additionally, presence of dysphagia (swallowing disorders) in brain-injured 
patients is also high (Although not specifically addressed in the current study as 
subjects with dysphagia were specifically excluded). It is highly probable that the 
combination of action errors with swallowing problems during mealtime may put the 
brain-injured subject at higher risk for choking or aspiration. Especially when it is 
considered that the most prevalent action errors were misuse and quantity. The 



118 

possibility of a brain-injured patient with dysphagia bringing a utensil to his/her 
mouth with too much or too little food is very possible and may result in exacerbation 
of the swallowing problem. 

The role of the speech-language pathologist (SLP) is an important one when 
action errors in the natural environment are discussed. The SLP is usually in a unique 
relationship with the brain-injured patient and their caregivers in that the SLP's main 
role is to improve the functional communication of the patient as well as to evaluate 
and treat dysphagia. By doing these tasks, the SLP becomes very familiar with the 
patient and their family and is often asked to interpret or reiterate instructions and 
conversations by other health care professionals. Through these close relationships, 
the SLP is accountable for providing ethical and professional care to the patient. The 
SLP's responsibilities often include counseling patients and caregivers, providing 
input to the rehabilitation team for discharge options, level of communication 
function, need of home health aids or assistance, as well as being an "intermediary" 
between the level of communication competence of the rehabilitation professionals 
and the level of communication competence of the brain-injured patient and their 
caregiver, who may be ignorant of the health care process. In these scenarios, the 
responsibility is also placed on the SLP to be accountable and knowledgeable for 
areas that may detrimentally affect their patient, of which production of action errors 
is one category. 



APPENDIX A 

FLORIDA APRAXIA BATTERY - GESTURE TO COMMAND SUBTEST 

RANDOMIZED FORM A 

NAME: DATE: 

Subjects will be required to provide a gesture to the given command. Subjects are to use 
the left (ipsilesional) hand to gesture. The first time the subject produces a body part as 
tool error, remind subject to pretend to hold and use the tool just as he normally would at 
home. Then allow to reattempt the gesture. Do not reinstruct on subsequent errors. 
Videotape all responses from a front view with subject seated in a chair. Although 
general performance may be scored on-line, actual scores will be derived from videotape 
viewing. 

Instructions: "I am going to ask you to make some gestures with your left hand. For some 
gestures you will just make different hand motions. For others you will pretend to use 
certain tools. Pretend to use each tool just as you would if you were actually holding the 
tool in your hand and using it." 

Show me: Score Error Code 

1 . how to use a scoop to serve ice cream. 

2. stop. 

3. how to use scissors to cut paper. 

4. OK. 

5. how to use wire cutters to snip a wire. 

6. how to use an ice pick to chop ice. 

7. how to use a comb to fix your hair. 

8. how you make a fist. 

9. how you wave good-bye. 

10. someone is crazy. 



119 



120 



FAB Gesture to Command, cont. 
Randomized form A 



NAME: 



1 1 . how to use a salt shaker to salt food. 

12. how to use a pencil to write on paper. 

13. how to use a glass to drink water. 

14. how you salute. 

15. how to use a hammer to pound a nail into a wall. 

16. how to use an eraser to clean a chalkboard. 

1 7. how to use a spoon to stir coffee. 

1 8. how to use a brush to paint the wall. 

19. how to use a screwdriver to turn a screw 

into the wall. 

20. how to use a bottle opener to remove a bottle cap. 

21. go away. 

22. how to use an iron to press a shirt. 

23. how to use a razor to shave your face. 

24. come here. 

25. how to use a knife to carve a turkey. 

26. how you hitchhike. 

27. be quiet. 

28. how to use a key to unlock a doorknob. 

29. how to use a saw to cut wood. 

30. how to use a vegetable peeler to shred a carrot. 



121 



FLORIDA APRAXIA BATTERY - GESTURE TO COMMAND SUBTEST 

RANDOMIZED FORM B 

NAME: DATE: 

Subjects will be required to provide a gesture to the given command. Subjects are to use 
the left (ipsilesional) hand to gesture. The first time the subject produces a body part as 
tool error, remind subject to pretend to hold and use the tool just as he normally would at 
home. Then allow to reattempt the gesture. Do not reinstruct on subsequent errors. 
Videotape all responses from a front view with subject seated in a chair. Although 
general performance may be scored on-line, actual scores will be derived from videotape 
viewing. 

Instructions: "I am going to ask you to make some gestures with your left hand. For some 
gestures you will just make different hand motions. For others you will pretend to use 
certain tools. Pretend to use each tool just as you would if you were actually holding the 
tool in your hand and using it." 

Show me: Score Error Code 

1 . how to use an eraser to clean a chalkboard. 

2. how to use a spoon to stir coffee. 

3 . how to use a brush to paint the wall. 

4. how to use a screwdriver to turn a screw into the wall. 

5. how to use a bottle opener to remove a bottle cap. 

6. go away. 

7. how to use an iron to press a shirt. 

8. how to use a razor to shave your face. 

9. come here. 

10. how to use a knife to carve a turkey. 

1 1 . how you hitchhike. 

12. be quiet. 



122 



FAB Gesture to Command, cont. NAME: 

Randomized form B 

1 3 . how to use a key to unlock a doorknob. _ 

1 4. how to use a saw to cut wood. _ 

15. how to use a vegetable peeler to 

shred a carrot. 

16. how to use a scoop to serve ice cream. _ 

17. stop. 

18. how to use scissors to cut paper. _ 

19. OK. _ 

20. how to use wire cutters to snip a wire. _ 

2 1 . how to use an ice pick to chop ice. 

22. how to use a comb to fix your hair. 

23. how you make a fist. 

24. how you wave good-bye. 

25. is cra2y. 

26. use a salt shaker to salt food. 

27. use a pencil to write on paper. 

28. use a glass to drink water. 

29. how you salute. 

30. how to use a hammer to pound a nail into a wall. 






APPENDIX B 



TOOL-OBJECT MATCHING TASK 



Procedure : Place the target tool and three foil tools in random order in front of the 
subject. Place the object with the partially completed action behind the tools. 
Instructions : "I am going to show you some tools and an object in which an action has not 
been completed. Please choose the tool that you would use to complete the action." 



Objects with partially 
completed action 

1. half opened can 

2. nail half in wood 

3. bit half in wood 

4. partially sawed board 

5. partially sewed cloth 

6. half drawn picture 

7. nail bent in wood 

8. partially cut paper 

9. screw half in wood 



Target 
tool 


Foil #1 


Foil #2 


can opener 


saw 


pen 


hammer 


screwdriver 


needle 


hand drill 


wrench 


staple remover 


saw 


hammer 


scissors 


needle 


can opener 


scissors 


pen 


needle 


hand drill 


hammer 


wrench 


saw 


scissors 


pen 


staple remover 


screwdriver 


wire 
cutters 


hammer 



10. staple half out of paper staple 

remover 



can opener wire cutters 



1 1 . partially cut wire 


wire cutters 


hand drill 


hammer 


12. nut & bolt partially 
tightened in wood 


wrench 


hammer 


screwdriver 



123 



APPENDIX C 



TRAILS TEST: Time in Seconds (on Parts A and B) for Normal Control Subjects 
at Different Age Levels 



15-20 

Years 

(n=108) 

Percentile A B 

90 15 26 

75 19 37 

50 23 17 

25 30 59 

10 38 70 



20-39 


40-49 


Years 


Years 


fn=275) 


(n=138) 


A B 


A B 


21 45 


18 30 


24 55 


23 52 


26 65 


30 78 


34 85 


38 102 


45 98 


59 126 



50-59 

Years 

(n=130) 



A 
23 
29 
35 



B 

55 
71 
80 



57 128 
77 162 



60-69 70-79 

Years Years 

fn=120) fn=90) 



A B 

26 62 

30 83 

35 95 



A 
33 
54 
70 



63 142 98 



B 

79 
122 
180 
210 



85 174 161 350 



Data extrapolated from Table 8-12 in Spreem and Strauss (1991) A Compendium of 
Neuropsychological Tests , London: Academic Press, p. 376. 



124 



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Churchill Livingstone. 



BIOGRAPHICAL SKETCH 

Beth Lynn Martin Macauley was born on December 9, 1965, in Sanford, Florida, 
to John L. and Barbara A. Martin. She has one younger brother, John William (Billy) 
Martin who is an architect in Charlotte, North Carolina. Beth married Shawn P. 
Macauley on June 18, 1988, in Port St. Lucie, Florida. They have two beautiful 
daughters, Erin Elizabeth born December 11, 1990, and Emily Logan, born February 23, 
1995, both in Gainesville, Florida, and one handsome son, Evan Alexander, born March 
29, 1998, in Spokane, Washington. 

Beth graduated from Ft. Pierce Central High School, Ft. Pierce, Florida, in June 
1983, ranked 12 th out of 364 graduates. She began her college career at the University of 
Florida in the fall of 1983 and graduated with a B.A. degree in speech-language 
pathology and audio logy in May 1987. Beth continued on in graduate school at the 
University of Florida and received her M.A. degree in speech-language pathology in 
December 1989. Her master's thesis was a unique study that combined her first love, 
speech pathology, with her main hobby, working with horses. The title was "The effects 
of hippotherapy on the respiration and motor speech functions of two females with 
cerebral palsy." Beth continued her training by completing the clinical fellowship year 
(CFY) in speech- language pathology in the Department of Communicative Disorders at 
W.A. Shands Hospital, Gainesville, Florida, under the supervision of Kenneth Bzoch, 
Ph.D., Lowell Hammer, Ph.D., and Michael Crary, Ph.D. Beth received her Certificate 



132 



133 

of Clinical Competence in speech- language pathology from the American Speech- 
Language-Hearing Association in October 1990. 

Following her CFY, Beth returned to full-time graduate work to pursue the 
doctoral degree under the mentorship of Leslie J. Gonzalez-Rothi, Ph.D., at the 
University of Florida. Beth's focus was on neurogenic communication disorders with 
special emphasis in neuropsychology. During her doctoral years, Beth worked as a 
research assistant for Kenneth M. Heilman, M.D., a behavioral neurologist in the 
Department of Neurology, University of Florida College of Medicine and the Center for 
Neuropsychological Studies. She also worked as a speech-language pathologist for 
Special Communications and Continental Medical Systems Therapies (now Pro-Rehab, 
Inc.). Special Communications served state institutions for mentally and physically 
handicapped people and CMS Therapies served two skilled nursing facilities the 
Gainesville area. 

From 1985 through 1994, Beth worked at Florida Horsemanship for Handicapped, 
Inc., as a junior instructor and therapist. She represented the program at the 6 
International Congress on Therapeutic Riding in Toronto, Ontario, August, 1988, and the 
North American Riding for the Handicapped Association convention in Parsippany, New 
Jersey, November, 1989. Beth was also active in the Florida Blue Key Honor Fraternity, 
serving as service chairman 1991-1992, the Collegiate 4-H Club, serving as secretary and 
vice-president 1984 and 1985, respectively, and the National Student Speech-Language- 
Hearing Association, serving as president for the 1987-88 school year. 

Toward the end of her doctoral program, Beth applied for various faculty 
positions and was extended an invitation to join the faculty in the Department of Speech 



134 

and Hearing Sciences at Washington State University, Spokane, Washington. Her 
husband was also extended an offer to join the Health Research and Education Center and 
the Department of Genetics and Cell Biology at Washington State University. They 
accepted and began work in December 1995. While in Spokane, Beth has worked as a 
weekend rotation and on-call speech-language pathologist for Empire Health Services 
which serves Sacred Heart Medical Center, Deaconess Medical Center, Valley Hospital 
and Medical Center, and St. Luke's Rehabilitation Institute. She is also a consultant 
speech-language pathologist for Paul J. Domitor, Ph.D., a Spokane based clinical 
psychologist and for A-Stride Ahead Therapy Services, a hippotherapy program in Deer 
Park, Washington. Upon completion of her Ph.D., Beth will continue as an Assistant 
Professor in the Department of Speech and Hearing Sciences at Washington State 
University. 

In Spokane, Beth is active at Garland Avenue Alliance Church, singing in King's 
Praise adult choir and playing flute with the worship orchestra. Her interests include 
riding and showing horses, playing the flute, sewing, cross-stitch, and baking. 



I certify that I have read this study and that in my opinion it conforms to 
acceptable standards of scholarly presentation and is fully adequate, in scope and quality, 
as a dissertation for the degree of Doctor of Philosophy. 




Associate 
Sciences and Di 



ation 



I certify that I have read this study and that in my opinion it conforms to 
acceptable standards of scholarly presentation and is fully adequate, in scope and quality, 
as a dissertation for the degree of Doctor of Philosophy. 




Kenneth M. Heilman 

Professor of Clinical and Health Psychology 



I certify that I have read this study and that in my opinion it conforms to 
acceptable standards of scholarly presentation and is fully adequate, in scope and quality, 
as a dissertation for the degree of Doctor of Philosophy. 





Bruce Crosson 

Professor of Clinical and Health Psychology 



I certify that I have read this study and that in my opinion it conforms to 
acceptable standards of scholarly presentation and is fully adequate, in scope and quality, 
as a dissertation for the degree of Doctor of Philosophy 




.inda-jT Lombardino 

fofessor of Communication Sciences and 
Disorders 









I certify that I have read this study and that in my opinion it conforms to 
acceptable standards of scholarly presentation and is fully adequate, in scope and quality, 
as a dissertation for the degree of Doctor of Philosophy. 




~9 

Ira Fischler 



Professor of Psychology 



This dissertation was submitted to the Graduate Faculty of the Department of 
Communication Processes and Disorders in the College of Liberal Arts and Sciences and 
to the Graduatre School and was accepted as partial fulfillment of the degree of Doctor of 
Philosophy. 

August 1998 



Dean, Graduate School 






R9& 



/Hll^ 









UNIVERSITY OF FLORIDA 



3 1262 08557 2104